Fema B Series User manual

Series B . Models Bxx-RTU
Meters for Modbus RTU
Large format industrial meters for Modbus RTU. Dierent formats available with 60 mm and 100 mm
digit height, 4 and 6 digits, in red or green color. Sturdy metal housing, with full IP65 protecon, designed
for panel, wall or hanging mount. Versale and congurable, accepts 16 and 32 bit registers, local or
remote alarm control, ‘watchdog’ funcon, ‘bus acvity’, congurable fast access menu, ‘on power up’
funcon, password and 5 congurable brightness levels. Universal AC and DC power. Accepts up to 3 out-
put and control opons (relays, analog retransmission, Modbus RTU, transistor outputs, RS-485 ASCII,
...). Conguraon from frontal keypad or remote keypad.
www.fema.es
INDUSTRIAL SERIES . LARGE FORMAT METERS
4381r03
User’s Manual
ELECTRONICS FOR INDUSTRIAL AUTOMATION
PANEL METERS . SIGNAL CONVERTERS . LARGE DISPLAYS

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
2
1. Series B, models Bxx-RTU
Large format industrial meters for Modbus RTU protocol
Large format meters for long distance reading, for industrial
applicaons. Dierent formats available with 4 and 6 digits,
with 60 mm and 100 m digit height. Front keypad to access
the conguraon menu, and oponal remote keypad.
Meters controlled via Modbus RTU protocol. Control of the
reading value, decimal point and alarm status, by wring to
internal registers. Standard Modbus RTU 16 bit registers for
readings from 32767 to -32767, and congurable to 32 bits
registers for readings from 999999 to -199999 (see secon
1.21.5).
Alarms can be congured for remote or local control by se-
lecng the ‘Full slave’ or ‘Process slave’ modes (see secon
1.21.2). In ‘Full slave’ mode alarms can be controlled by writ-
ing to registers or to coils (see secon 1.21.6).
Bus speed up to 38.400 bps and addresses from 1 to 247.
‘Watchdog’ funcon to control loss of communicaon with
the master, with control of error message and alarm acva-
on (see secon 1.21.4).
‘Bus acvity’ funcon for help on communicaons start-up
(see secon 1.21.12).
Output and control opons with 1, 2 and 3 relays, transis-
tor outputs, controls for SSR relays, isolated analog outputs,
communicaons in Modbus RTU, RS-485 ASCII and RS-232.
Sturdy metal housing with full IP65 protecon. Internal
connecons by plug-in screw clamp terminals, and output
through cable glands. Housing prepared for panel, wall and
hanging mount.
• Congurable ‘Fast access’ to selected funcons with key
‘UP’ (5) (see secon 1.21.11)
• ‘On power up’ for system protecon on ‘cold’ start-up and
control of alarm status (see secon 1.21.13)
• alarms in ‘Process slave’ mode, with 1 or 2 setpoints, in-
dependent acvaon and deacvaon delays, hysteresis,
manual unlocking, ... (see secon 1.21.8)
Memory of maximum and minimum reading, password pro-
tecon, 5 brightness levels.
1.1 How to order
B24 RTU
Model Power
-H -
Opon 1
- -
Opon 2
-
Opon 3*
-R1 (1 relay)
-AO (analog output)
-RTU (Modbus RTU)
-S4 (RS-485)
-S2 (RS-232)
-T1 (1 transistor)
-SSR (1 control SSR)
-0 (empty)
-H (85-265 Vac
and 120-370 Vdc)
-L
(11-36 Vdc isolated)
Color
-
-R (red led)
-G
(green led)
B24 (60 mm, 4 digits)
B26 (60 mm, 6 digits)
B44
(100 mm, 4 digits)
B46
(100 mm, 6 digits)
Others
-
Format
*Opon 3 available
with formats B26 and
B46

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
3
1. Series B, models Bxx-RTU . . . . . . . . . . . . . . . . . 2
1.1 How to order . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 How to use this manual . . . . . . . . . . . . . . . . 4
1.4 Modbus RTU denions . . . . . . . . . . . . . . . . 4
1.5 Typical applicaon . . . . . . . . . . . . . . . . . . . 5
1.6 Factory conguraon . . . . . . . . . . . . . . . . . . 5
1.7 Sizes and formats . . . . . . . . . . . . . . . . . . . . 6
1.7.1 Format B24. . . . . . . . . . . . . . . . . . . . . . 6
1.7.2 Format B44. . . . . . . . . . . . . . . . . . . . . . 6
1.7.3 Format B26. . . . . . . . . . . . . . . . . . . . . . 7
1.7.4 Format B46. . . . . . . . . . . . . . . . . . . . . . 7
1.8 To access the instrument . . . . . . . . . . . . . . . . 8
1.9 Modular system . . . . . . . . . . . . . . . . . . . . . 8
1.10 Power connecons and protecve earth . . . . . . 9
1.11 Input signal connecons . . . . . . . . . . . . . . . 9
1.12 Connecons for remote keypad . . . . . . . . . . . 9
1.13 Technical specicaons . . . . . . . . . . . . . . . 10
1.14 Funcons included . . . . . . . . . . . . . . . . . 11
1.15 Messages and errors . . . . . . . . . . . . . . . . 11
1.16 Start up sequence . . . . . . . . . . . . . . . . . . 11
1.17 Registers and funcons : 16 bits ‘Process slave’ . 12
1.18 Registers and funcons : 16 bits ‘Full Slave’ . . . . 13
1.19 Registers and funcons : 32 bits ‘Process slave’ . 14
1.20 Registers and funcons : 32 bits ‘Full Slave’ . . . . 15
1.21 Conguraon . . . . . . . . . . . . . . . . . . . . 16
1.21.1 How to operate the menus . . . . . . . . . . . 16
1.21.2 Inial set-up . . . . . . . . . . . . . . . . . . . 17
1.21.3 Addresses. . . . . . . . . . . . . . . . . . . . . 18
1.21.4 ‘Watchdog’ funcon . . . . . . . . . . . . . . . 18
1.21.5 16 bits or 32 bits registers. . . . . . . . . . . . 18
1.21.6 Alarm control : registers and ‘coils’ . . . . . . . 18
1.21.7 Conguraon menu . . . . . . . . . . . . . . . 19
1.21.8 Alarms . . . . . . . . . . . . . . . . . . . . . . 20
1.21.9 Alarms conguraon menu for ‘full slave’ . . . 21
1.21.10 Alarms conguraon menu for ‘process slave’ 21
1.21.11 Fast access . . . . . . . . . . . . . . . . . . . 22
1.21.12 ‘Bus acvity’ funcon . . . . . . . . . . . . . 22
1.21.13 ‘On power up’ funcon . . . . . . . . . . . . 22
1.21.14 ‘Setpoint on bus’ parameter. . . . . . . . . . 22
1.21.15 ‘Decimal point’ parameter. . . . . . . . . . . 22
1.21.16 ‘Fast access’ conguraon menu . . . . . . . 23
1.21.17 ‘On power up’ conguraon menu . . . . . . 23
1.21.18 Setpoint on bus’ conguraon menu . . . . . 23
1.21.19 ‘Decimal point’ conguraon menu . . . . . 23
1.21.20 ‘Key LE’ conguraon menu . . . . . . . . . . 24
1.21.21 Password conguraon . . . . . . . . . . . . 24
1.21.22 Default factory conguraon . . . . . . . . . 24
1.21.23 Firmware version . . . . . . . . . . . . . . . . 24
1.21.24 Brightness conguraon . . . . . . . . . . . . 24
1.21.25 Access to the opons conguraon menu . . 25
1.22 Full conguraon menu. . . . . . . . . . . . . . . 26
1.23 Mounng. . . . . . . . . . . . . . . . . . . . . . . 28
1.24 Installaon precauons . . . . . . . . . . . . . . . 29
1.25 Warranty . . . . . . . . . . . . . . . . . . . . . . . 29
1.26 CE declaraon of conformity . . . . . . . . . . . . 29
2. Output and control modules . . . . . . . . . . . . . . 30
2.1 Module R1 . . . . . . . . . . . . . . . . . . . . . . . 30
2.2 Module T1 . . . . . . . . . . . . . . . . . . . . . . . 30
2.3 Module SSR . . . . . . . . . . . . . . . . . . . . . . 31
2.4 Module AO . . . . . . . . . . . . . . . . . . . . . . 31
2.5 Module RTU . . . . . . . . . . . . . . . . . . . . . . 32
2.6 Module S4 . . . . . . . . . . . . . . . . . . . . . . . 32
2.7 Module S2 . . . . . . . . . . . . . . . . . . . . . . . 33
3. Other opons and accessories . . . . . . . . . . . . . 34
3.1 RKB - Remote keypad. . . . . . . . . . . . . . . . . 34
3.2 Red LED . . . . . . . . . . . . . . . . . . . . . . . . 34
3.3 Green LED . . . . . . . . . . . . . . . . . . . . . . . 34
1.2 Index

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
4
1. Idenfy the instrument format (see secon 1.7)
2. Power and signal connecons
- open the instrument (see secon 1.8)
- connect the power (see secon 1.10)
- connect the signal (see secon 1.11)
- close the instrument (see secon 1.8)
3. Congure the instrument (see secon 1.21)
- select the working mode, and the bus conguraon (see
secon 1.21.2)
- congure the protocol (see secon 1.21.7)
4. Advanced conguraon (oponal)
- congure the instrument alarms (see secon 1.21.8)
- congure the fast access (see secon 1.21.11)
- congure other funcons: ‘on power up’ (1.21.13), key
‘LE’ (1.21.20) and password (1.21.21)
5. If the instrument includes analog output (AO) or serial
communicaons (RTU, S4, S2)
- to include an opon to an instrument see secon 1.9
- to congure an installed opon, access the opon con-
guraon menu (see secon 1.21.25)
- see secon 2 for informaon regarding the output and
control opons available
6. Install the instrument
- mount on panel, wall or hanging (see secon 1.23)
- adjust the brightness level according to your environmen-
tal needs (see secon 1.21.24)
1.3 How to use this manual
If this is the rst me you are conguring a Series B large
format meter, below are the steps to follow to install and
congure the instrument. Read all the manual secons in
order to have a full and clear view of the characteriscs of
the instrument. Do not forget to read the installaon precau-
ons at secon 1.24.
The Modbus RTU protocol is a serial communicaons proto-
col, based on RS-485 bus, with ‘master’ / ‘slave’ architecture.
Modbus RTU elements needed to understand this manual
are described below:
• ‘registers’: are memory secons inside the ‘slave’ in-
strument, where the ‘master’ reads or writes data. Reg-
isters store numerical data. Modbus works with registers
of 16 bits, which allows for numerical values from 32767
to -32767. For displays with 6 digits (display values from
999999 to -199999) registers of 32 bits are needed (see
secon 1.21.5).
• ‘coils’: are memory secons inside the ‘slave’ instrument,
where the ‘master’ reads or writes data. Coils store binary
data (‘1’ or ‘0’). Coils are typically used for alarm control
and other elements with 2 states : ‘on’ and ‘o’.
• ‘funcons’: are acons that indicate to write or read val-
ues into ‘registers’ or ‘coils’ (see Table 1).
• ‘errors’ : Modbus is a protocol with a ‘master’ / ‘slave’ ar-
chitecture and the ‘master’ will always expect a reply from
the ‘slave’. If a requested ‘funcon’, ‘register’ or ‘coil’ is not
available, the ‘slave’ will answer with an error. See secon
1.15 for a list of errors available.
1.4 Modbus RTU denions
Funcon Name Descripon
6Write single register writes on a single register
16 Write mulple regis-
ters
writes on mulple registers
3Read registers reads on mulple registers
5 Write single coil writes on a single coil
15 Write mulple coils writes on mulple coils
1 Read coils reads on mulple coils
Table 1 - Modbus RTU supported funcons

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
5
1.5 Typical applicaon
The typical applicaon for this models of large format indus-
trial meters if to display numerical values associated to the
producon or industrial processes. Display value is controlled
through the Modbus RTU protocol. Modbus RTU messages
are sent by the bus master, usually a PLC or a SCADA system.
The instrument can also integrate relay outputs, which
can be remotely controlled from the ‘master’ (‘Full slave’
working mode (see secon 1.21.2)) or locally controlled by
the instrument (‘Process slave’ working mode (see secon
1.21.2)).
Addional analog outputs can be also installed . See secon
2 for a list of oponal output and control modules available.
Modbus RTU
Relay 1
Relay 2
4/20mA
(isolated)
1.6 Factory conguraon
Working mode ‘Full slave’ (‘F.SLV’)
Bus
Speed 19200 bps
Format 8n1
Conguraon
Local address 1
‘Watchdog’ 10 seconds
‘On error’ ash (‘FLSh’)
Data length 16 bits
Alarm control by coil
Alarms in ‘Full slave’ mode
Alarm 1 remote (‘rMtE’)
Alarm 2 remote (‘rMtE’)
Alarm 3 remote (‘rMtE’)
Alarms in ‘Process slave’ mode
Alarms 1,2 and 3
Acve disabled (‘oFF’)
Type maximum
Setpoint 1000
Hysteresis 0 counts
Acvaon delay 0.0 seconds
Deacvaon delay 0.0 seconds
Setpoint 2 o
Inverted relay o
Locked alarms o
Tools
Fast access (
Key UP
) o
Bus acvity o
Memory of maximum o
Memory of minimum o
Alarm 1 o
Alarm 2 o
Alarm 3 o
Address o
‘On Power Up’
Delay 0 seconds
Alarm 1 o
Alarm 2 o
Alarm 3 o
Setpoint on bus o
Decimal point remote (‘rMtE’)
Key ‘LE’ no funcon (‘none’)
Password o
Brightness 3

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
6
1.7 Sizes and formats
1.7.1 Format B24
Size A 340 mm
Size B 135 mm
Size C 3 mm
Size D 55 mm
Size E 25 mm
Table 2 - Sizes B24
Cut-out G 322 mm (±1)
Cut-out F 117 mm (±1)
Table 3 - Panel cut-out B24
A
Power
Opon 2 Opon 1
Remote keypad
Signal
Power
Slot for opon 2
Slot for opon 1
Input signal terminal
Remote keypad terminal
CDE
Cable glands
B
F
G
Panel cut-out
(see Table 3)
1.7.2 Format B44
Size A 542 mm
Size B 166 mm
Size C 3 mm
Size D 55 mm
Size E 25 mm
Table 4 - Sizes B44
Cut-out G 524 mm (±1)
Cut-out F 148 mm (±1)
Table 5 - Panel cut-out B44
Power
Opon 2 Opon 1
Remote keypad
Signal
CDE
A
B
F
G
Panel cut-out
(see Table 5)

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
7
1.7.3 Format B26
B
A
Power
Opon 3 Opon 2
Remote keypad
SignalOpon 1
CDE
Cable glands
Power
Slot for opon 3
Slot for opon 2
Input signal terminal
Remote keypad terminal
Slot for opon 1
Size A 436 mm
Size B 135 mm
Size C 3 mm
Size D 55 mm
Size E 25 mm
Table 6 - Sizes B26
Cut-out G 418 mm (±1)
Cut-out F 117 mm (±1)
Table 7 - Panel cut-out B26
F
G
Panel cut-out
(see Table 7)
1.7.4 Format B46
CDE
B
A
Power
Opon 3 Opon 2
Remote keypad
SignalOpon 1
Size A 740 mm
Size B 166 mm
Size C 3 mm
Size D 55 mm
Size E 25 mm
Table 8 - Sizes
B46
Cut-out G 722 mm (±1)
Cut-out F 148 mm (±1)
Table 9 - Panel cut-out B46
F
G
Panel cut-out
(see Table 9)

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
8
1.8 To access the instrument
To open the housing, remove the screws from the back cov-
er. With each screw there is a metal washer and a plasc
washer. Once the screws are out, remove the back cover.
The gure below shows the instrument internal structure for
a B26 format. It shows the locaon of the 3 slots for oponal
output and control modules, the power terminal and the in-
put signal terminal.
To close the instrument, place the back cover, the screws,
the metal washer and the plasc washer. The plasc washer
is in contact with the back cover. Conrm that the screws are
correctly turning inside the internal female screws.
To ensure a correct IP65 protecon ghten the back cover
screws with a strength between 30 and 40 Ncm, with the
help of a dynamometer screwdriver.
1.9 Modular system
Large format meters from Series B are designed with an in-
ternal modular architecture. The output and control mod-
ules are independent and can be installed by accessing the
internal circuits of the instrument, and connecng the mod-
ule to the connecon jumpers of the selected slot.
Each module is provided with a cable e to x the module
to the e base. The input signal modules denes the instru-
ment funcon and are exchangeable, switching a tempera-
ture meter to an impulse counter only by replacing the input
signal module.
See secon 2. for informaon regarding the output and con-
trol opons available
To install an output and control module
(1) insert the ‘module pins’ into the
‘connecon jumpers’ in one of the
free slots
(2) place the ‘cable e’ into the ‘e
base’ and embrace the ‘module’
rmly, unl it is xed
Slot 1
Slot 2
Slot 3
Connecon jumpers
Tie base
Cable e
(1)
(2)
Module pins
Output and control module
Power
Slot for opon 1
Slot for opon 2
Input signal terminal
Remote keypad terminal
Slot for opon 3Back cover
Female turret
Waterght seal
Screw
Metal washer
Plasc washer
Observe precauons for handling ESD (elec-
trostac discharge) sensive devices
Risk of electric shock. Removing the back
cover will grant access to the internal cir-
cuits of the instrument. Operaon must be
performed by qualied personnel only.

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
9
1.10 Power connecons and protecve earth
1. Unscrew the screws from the back cover and remove the
back cover (see secon 1.8).
2. Pass the power cable through the power cable gland (see
secon 1.7).
3. Prepare the power cables so that the earth wire is 20 cm
longer than the other cables (see Figure 1).
4. Connect the earth wire to the internal xed screw ‘PE’
(see Figure 2) located at the inside of the back cover. The
instrument internally connects the back cover metallic
Phase (+)
Neutral (-)
Earth
20 cm
Figure 1 - Longer earth wire
Power cable gland
Screws
‘PE’ internal xed screw
Figure 2 - Locaon of the internal ‘PE’ xed screw and power cable gland
structure with the front metallic structure through an in-
ternal green-yellow cable. (doed cable at Figure 3).
5. Connect phase and neutral (in AC power) or posive and
negave (in DC power) to the internal power terminal.
6. The connecons label aached to the outside of the in-
strument has some free space le to write the color or
local code for each cable.
7. To comply with security regulaon 61010-1, add to the
power line a protecon fuse acng as a disconnecon
element, easily accessible to the operator and idened
as a protecon device.
Power ‘H’ 500 mA me-lag fuse
Power ‘L’ 1000 mA me-lag fuse
Power Terminal
(orange)
NL
PE
PE
fuse
Figure 3 - Power connecons
1. Unscrew the screws from the back cover and remove the
back cover (see secon 1.8).
2. Locate the input signal terminal (see secon 1.7).
3. Pass the signal cable through the signal cable gland (see
secon 1.7).
4. Connect the input signal cables (see Figure 4).
5. The connecons label aached to the outside of the in-
strument has some free space le to write the color or
local code for each cable.
1.11 Input signal connecons
B
A
2
3
GND
Input Signal
1
ARS-485 A wire
BRS-485 B wire
GND Shield
Figure 4 - Signal connecons
The 4 pin terminal located beside
the input signal module allows to
replicate a remote version of the
front keypad. Connect 4 cables
for front keys ‘SQ’ (<), ‘UP’ (5)
and ‘LE’ (3) and for the com-
mon. Pass these cables through
the ‘remote keypad’ cable gland
(see secon 1.7)
.
GND
SQ
UP
LE
1.12 Connecons for remote keypad

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
10
Format B24 Format B44 Format B26 Format B46
Number of digits 4 4 6 6
Digit height 60 mm 100 mm 60 mm 100 mm
Reading distance 25 meters 50 meters 25 meters 50 meters
Slots for output and control opons 2 2 3 3
Maximum reading 9999 999999
Minimum reading -1999 -199999
Consumpon (without opons installed) 3 W 5.25 W 3.5 W 5.5 W
Consumpon (with opons installed) 5 W 6.75 W 5,5 W 7 W
Weight 2200 gr. 2500 gr. 3500 gr. 4500 gr.
Table 10 - Technical specicaons associated to format
Digits
number of digits 4 or 6 (see Table 10)
digit 7 segments
view angle 120º
color red or green
digit height (see Table 10)
Reading
max., min. (see Table 10)
decimal point X.X.X.X.X.X.
Protocol Modbus RTU
funcon slave within a Modbus RTU bus
speed from 38.400 bps to 600 bps
data formats 8n1, 8e1, 8o1, 8n2
addresses 1 to 247
bus terminator not included
wire secon max. 0.5 mm2
Watchdog congurable from 1 to 120 sec.
Errors communicaon loss with the
master
Power
power ‘H’ 85 to 265 Vac and 120 to 370 Vdc
isolated (isolaon 2500 Vac)
power ‘L’ 11 to 36 Vdc isolated
(isolaon 1500 Vdc)
consumpon (see Table 10)
fuses (see secon 1.10)
wire secon max. 2.5 mm2
1.13 Technical specicaons
Conguraon front keypad with 3 keys
remote keypad (see secon 3.1)
Output and control opons
relay output, analog retransmission,
Modbus RTU, ... (see secon 2)
Mechanical
IP protecon full IP65 housing
mounng panel, wall , hanging (see secon
1.23)
connecons cable gland outputs
internal plug-in screw terminals
housing material
textured iron, black painted
methacrylate front lter
weight (see Table 10)
front sizes (see secon 1.7)
panel cut-out (see secon 1.7)
depth (see secon 1.7)
Temperature
operaon from 0 to +50 ºC
storage from -20 to +70 ºC
warm-up me 15 minutes

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
11
Funcons included Secon
Local or remote
alarms yes, congurable 1.21.8
Address congurable 1.21.3
Watchdog yes, congurable 1.21.4
Watchdog error yes, congurable 1.21.4
Registers 16 or 32 bits 1.21.5
Remote alarms by ‘coil’ or ‘register’ 1.21.6
Local alarms
simple or double setpoint
acvaon delays
deacvaon delays
hysteresis
inverted relays
locked alarms
1.21.8
Fast access menu yes, congurable 1.21.11
‘Bus acvity’ yes 1.21.12
‘On Power Up’ yes 1.21.13
‘Setpoint on bus’ yes 1.21.14
‘Decimal point’ yes 1.21.15
Key ‘LE’ yes 1.21.20
Password conguraon locked 1.21.21
Brightness
congurable, 5 levels 1.21.24
Table 11 - Funcons included
1.14 Funcons included
Error messages related to the local instrument are shown on
display, in ash mode (see Table 12). Examples given are for
instrument with 6 digit formats. Error messages related to
the protocol are sent as response frames through the com-
municaons bus (see Table 13).
1.15 Messages and errors
Messages and errors on display
‘Err.1’ incorrect password.
‘Err.2’ at ‘oPt.X’ menu entry. Installed module is not
recognized.
‘Err.W’ ‘Watchdog’ error
‘999999’ + ashing mode. Reading is in overrange.
‘-199999’ + ashing mode. Reading is in underrange.
Table 12 - Messages and error codes for local instrument
Messages and errors on the Modbus RTU protocol
1‘Illegal funcon’. Funcon requested is not avail-
able.
2‘Illegal data’. Register or coil requested is not
available.
Table 13 - Messages and error codes for the Modbus RTU protocol
1.16 Start up sequence
The instrument follows the sequence indicated below at
start-up aer a power loss :
1. alarm status according to conguraon (see secon
1.21.13)
2. start up delay according to conguraon (see secon
1.21.13)
3. all registers and coils inialized to value ‘0’
3.1 display set to ‘0’
4. detecon of the acve working mode ‘Full slave’ or ‘Pro-
cess slave’ (see secon 1.21.2)
4.1 in ‘Full slave’ mode the alarm status is set as explained
in ‘1.’ and alarm registers are set to ‘0’
4.2 in ‘Process slave’ mode alarm conguraon (setpoint,
etc) is compared with display value (‘0’) and each alarm
acvates or deacvates according to the result of the
comparison
5. waits for data recepon through the communicaons
bus

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
12
1.17 Registers and funcons : 16 bits ‘Process slave’
List of available registers (see Table 14) and available func-
ons (see Table 15) for instruments congured in ‘Process
slave’ mode and 16 bits data length.
• accessing a funcon not listed in the table, returns error
1 ‘Illegal Funcon’.
• accessing a register not listed in the table, returns error 2
‘Illegal Data Address’.
• working with 16 bit registers allows for codicaon of
numbers between 32767 and -32767. To work with num-
bers up to 999999 / -199999, congure registers for 32 bits
data (see secon 1.21.5).
• registers Setpoint 1, Setpoint 2 and Setpoint 3 are dis-
abled by default (setpoint value is modied through the
front keypad). To enable access to read and write these
registers through the bus, while staying in ‘Process slave’
mode, see secon 1.21.14.
- wring to the setpoint registers when they are disabled
returns error 2 ‘Illegal Data Address’.
- modifying a setpoint value manually from the front key-
pad, does not update the value stored at the setpoint
register. Reading the setpoint register does not access the
setpoint value congured in the instrument, but the last
wrien value on the register.
• aer power loss, the instrument starts up with all regis-
ters inialized to ‘0’ (see secon 1.16).
• the ‘Resoluon’ register contains a numerical value indi-
cang the number of decimal places on display. Valid val-
ues from 0 to 5. Wring value 2 lights the decimal point at
posion XXXX.XX. Non valid values are discarded and no
error message is generated.
• all registers are read and write registers.
• access to reserved registers does not generate error mes-
sages.
Example - to update the display of the instrument to a value
of 432.1, write onto ‘Display’ register the number ‘4321’ and
write onto ‘Resoluon’ register the number ‘1’.
Register ‘Display’ : ‘4321’
Register ‘Resoluon’ : ‘1’
Register number Name
0 Display
1 Resoluon
2 Setpoint 1*
3 Setpoint 2*
4 Setpoint 3*
5 Reserved
Table 14 - Registers in 16 bits and ‘Process slave’ mode
Funcon number Name
6 Write single register
16 Write mulple registers
3Read registers
Table 15 - Funcons in 16 bits and ‘Process slave’ mode

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
13
1.18 Registers and funcons : 16 bits ‘Full Slave’
List of available registers (see Table 16), available ‘coils’ (see
Table 17) and available funcons (see Table 18) for instru-
ments congured in ‘Full slave’ mode and 16 bits data length.
• accessing a funcon not listed in the table, returns error
1 ‘Illegal Funcon’.
• accessing a register not listed in the table, returns error
2 ‘Illegal Data Address’.
• working with 16 bit registers allows for codicaon of
numbers between 32767 and -32767. To work with num-
bers up to 999999 / -199999, congure registers for 32 bits
data (see secon 1.21.5).
• aer power loss, the instrument starts up with all regis-
ters inialized to ‘0’ (see secon 1.16).
• the ‘Resoluon’ register contains a numerical value indi-
cang the number of decimal places on display. Valid val-
ues from 0 to 5. Wring value 2 lights the decimal point at
posion XXXX.XX. Non valid values are discarded and no
error message is generated.
• alarms can be controlled using ‘Alarm’ registers or ‘coils’.
By default, alarms are controlled by coils(see Table 17). To
enable the ‘Alarm’ register see secon 1.21.6. The ‘Alarm’
register is made of bits. Bit ‘0’ controls the state of Alarm 1,
bit ‘1’ control the state of Alarm 2 and bit ‘2’ controls the
state of Alarm 3
• all registers are read and write registers.
• access to reserved registers does not generate error
messages.
Register number Name
0 Display
1 Resoluon
2 Alarms
3
4
5
Reserved
Table 16 - Registers in 16 bits and ‘Full Slave’ mode
‘Coil’ number Name
0 Alarm 1
1 Alarm 2
2 Alarm 3
3
4
5
6
7
Reserved
Table 17 - ‘Coils’ in 16 bits and ‘Full Slave’ mode
Funcon number Name
6Write single register
16 Write mulple registers
3Read registers
5 Write single ‘coil’
15 Write mulple ‘coils’
1 Read ‘coils’
Table 18 - Funcons in 16 bits and ‘Full Slave’ mode
Example - to update the display of the instrument to a value
of 432.1, write onto ‘Display’ register the number ‘4321’ and
write onto ‘Resoluon’ register the number ‘1’.
Register ‘Display’ : ‘4321’
Register ‘Resoluon’ : ‘1’

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
14
1.19 Registers and funcons : 32 bits ‘Process slave’
List of available registers (see Table 19) and available func-
ons (see Table 20) for instruments congured in ‘Process
slave’ mode and 32 bits data length.
• accessing a funcon not listed in the table, returns error
1 ‘Illegal Funcon’.
• accessing a register not listed in the table, returns error
2 ‘Illegal Data Address’.
• working with 16 bit registers allows for codicaon of
numbers between 32767 and -32767. If higher or lower
values are codied into a register, it will force the instru-
ment to overrange or underrange the reading.
• registers Setpoint 1, Setpoint 2 and Setpoint 3 are dis-
abled by default (setpoint value is modied through the
front keypad). To enable access to read and write these
registers through the bus, while staying in ‘Process slave’
mode, see secon 1.21.14.
- wring to the setpoint registers when they are disabled
returns error 2 ‘Illegal Data Address’.
- sending values higher than 999999 (or lower than
-199999) to the setpoint registers will save the value
999999 (or -199999)
- modifying a setpoint value manually from the front key-
pad, does not update the value stored at the setpoint
register. Reading the setpoint register does not access the
setpoint value congured in the instrument, but the last
wrien value on the register.
• aer power loss, the instrument starts up with all regis-
ters inialized to ‘0’ (see secon 1.16).
• registers of 32 bits are wrien with funcon ‘Write Mul-
ple Registers’. Both registers (‘high’ and ‘low’) must be
wrien with the same write funcon. If write funcon is
received only for one of the registers (‘high’ or ‘low’) the
instrument will discard the write funcon. No error code
will be generated.
• the ‘Resoluon’ register contains a numerical value indi-
cang the number of decimal places on display. Valid val-
ues from 0 to 5. Wring value 2 lights the decimal point at
posion XXXX.XX. Non valid values are discarded and no
error message is generated.
• all registers are read and write registers.
• access to reserved registers does not generate error
messages.
Example - to update the display of the instrument to a value
of 6543.21, it is needed to work with 32 bits registers. Con-
vert the value to hex format and write to the ‘Display high’
register the rst 16 bits and to the ‘Display low’ register the
last 16 bits.
654321 decimal translated to hexadecimal is 0x0009FBF1
register ‘display high’ = 0x0009 = ‘9’
register ‘display low’ = 0xFBF1 = ‘64497’
When programming, this is directly achieved with funcons
DIV (integer division) and MOD (rest of integer division).
register ‘display high’ = 654321 DIV 65536 = 9
register ‘display low’ = 654321 MOD 65536 = 64497
register ‘resoluon high’ = 0
register ‘resoluon low’ = 2
Register number Name
0 Display Low
1 Display High
2 Resoluon Low
3 Resoluon High
4 Setpoint 1 Low
5 Setpoint 1 High
6 Setpoint 2 Low
7 Setpoint 2 High
8 Setpoint 3 Low
9 Setpoint 3 High
10 Reserved
11 Reserved
Table 19 - Registers in 32 bits and ‘Process slave’ mode
Funcon number Name
16 Write mulple registers
3Read registers
Table 20 - Funcons in 32 bits and ‘Process slave’ mode

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
15
1.20 Registers and funcons : 32 bits ‘Full Slave’
List of available registers (see Table 21), available ‘coils’ (see
Table 22) and available funcons (see Table 23) for instru-
ments congured in ‘Full slave’ mode and 32 bits data length.
• accessing a funcon not listed in the table, returns error
1 ‘Illegal Funcon’.
• accessing a register not listed in the table, returns error
2 ‘Illegal Data Address’.
• working with 16 bit registers allows for codicaon of
numbers between 32767 and -32767. If higher or lower
values are codied into a register, it will force the instru-
ment to overrange or underrange the reading.
• aer power loss, the instrument starts up with all regis-
ters inialized to ‘0’ (see secon 1.16).
• registers of 32 bits are wrien with funcon ‘Write Mul-
ple Registers’. Both registers (‘high’ and ‘low’) must be
wrien with the same write funcon. If write funcon is
received only for one of the registers (‘high’ or ‘low’) the
instrument will discard the write funcon. No error code
will be generated.
• the ‘Resoluon’ register contains a numerical value indi-
cang the number of decimal places on display. Valid val-
ues from 0 to 5. Wring value 2 lights the decimal point at
posion XXXX.XX. Non valid values are discarded and no
error message is generated.
• alarms can be controlled using ‘Alarm’ registers or ‘coils’.
By default, alarms are controlled by coils(see Table 17). To
enable the ‘Alarm’ register see secon 1.21.6. The ‘Alarm’
register is made of bits. Bit ‘0’ controls the state of Alarm 1,
bit ‘1’ control the state of Alarm 2 and bit ‘2’ controls the
state of Alarm 3
• all registers are read and write registers.
• access to reserved registers does not generate error
messages.
Register number Name
0 Display Low
1 Display High
2 Resoluon Low
3 Resoluon High
4 Alarms Low
5 Alarm as High
6 a 11 Reserved
Table 21 - Registers in 32 bits and ‘Full slave’ mode
‘Coil’ number Name
0 Alarm 1
1 Alarm 2
2 Alarm 3
3
4
5
6
7
Reserved
Table 22 - ‘Coils’ in 32 bits and ‘Full Slave’ mode
Funcon number Name
16 Write mulple registers
3Read registers
5 Write single ‘coil’
15 Write mulple ‘coils’
1 Read ‘coils’
Table 23 - Funcons in 32 bits and ‘Full Slave’ mode
Example - to update the display of the instrument to a value
of 6543.21, it is needed to work with 32 bits registers. Con-
vert the value to hex format and write to the ‘Display high’
register the rst 16 bits and to the ‘Display low’ register the
last 16 bits.
654321 decimal translated to hexadecimal is 0x0009FBF1
register ‘display high’ = 0x0009 = ‘9’
register ‘display low’ = 0xFBF1 = ‘64497’
When programming, this is directly achieved with funcons
DIV (integer division) and MOD (rest of integer division).
register ‘display high’ = 654321 DIV 65536 = 9
register ‘display low’ = 654321 MOD 65536 = 64497
register ‘resoluon high’ = 0
register ‘resoluon low’ = 2

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
16
The instrument has two menus accessible to the user :
‘Conguraon menu’ (key ‘SQ’) (<)
‘Fast access’ menu (key ‘UP’) (5)
Conguraon menu
The ‘conguraon menu’ modies the conguraon param-
eters to adapt the instrument to the applicaon needs. To
access the ‘conguraon menu’ press for 1 second the ‘SQ’
(<) key. This access can be blocked by acvang the ‘Pass-
word’ (‘PASS’) funcon. While operang the ‘conguraon
menu’, the alarm status is ‘hold’ to the status it had before
accessing the menu, and the output and control modules re-
main in ‘error’ state. When leaving the ‘conguraon menu’,
the instrument applies a system reset, followed by a brief
disconnecon of the alarms and the output and control
modules. Funconality is then recovered.
For a detailed explanaon on the ‘conguraon menu’ see
the following secons, and for a full view of the ‘congura-
on menu’ see secon 1.22.
‘Fast access’ menu
The ‘fast access’ menu is an operator congurable menu,
providing fast and direct access to the most usual funcons
of the instrument with a single key pad stroke. Press key ‘UP’
(5) to access this menu.
See secon 1.21.11 for a list of selectable funcons for the
‘fast access’ menu in this instrument. The ‘Password’ (‘PASS’)
funcon does not block access to this menu. Accessing and
modifying parameters in the ‘fast access’ menu does not in-
terfere with the normal funconality of the instrument, and
it does not generate any system reset when validang the
changes.
Operang with the front keypad inside the menus
Key ‘SQ’ (<) - press the ‘SQ’ (<) key for 1 second to access
the ‘conguraon menu’. Inside the menu, the ‘SQ’ (<) key
acts as an ‘ENTER’. It enters into the menu opon selected,
and when entering a numerical value, it validates the num-
ber.
Key ‘UP’ (5) - press the ‘UP’ (5) key to access the ‘fast ac-
cess’ menu. Inside the menu,the ‘UP’ (5) key sequenally
moves through the available parameters and menu entries.
When entering a numerical value, it modies the digit se-
lected by increasing its value to 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
1.21 Conguraon
1.21.1 How to operate the menus
Key ‘LE’ (3) - press the ‘LE’ (3) key to acvate the cong-
ured special funcons associated to this key. Inside the menu,
the ‘LE’ (5) acts as an ‘ESCAPE’. It leaves the selected menu
level and eventually, by leaving all menu levels, it leaves from
the conguraon menu. Then changes are applied and the
instrument is back to normal funcon. When entering a nu-
merical value, it selects the acve digit, and the value is then
modied by key ‘UP’ (5).
‘Rollback’
Aer 30 seconds without interacon from the operator, the
instrument will rollback and leave the ‘conguraon menu’
or the ‘fast access’ menu. All changes will be discarded.
Instruments with 4 and 6 digits
The conguraon menus included in this document show
values for a 6 digit instrument. In case of 4 digit instruments,
note that maximum reading values should be 9999 instead
of 999999 to 9999 and minimum reading values should be
-1999 instead of -199999.
(2)
(3)
(3)
(3)
(3)
(3)
(4)
(4)
(4)
(4)
(5)
(5)
(5)
(5)
(3)
(3)
(6)
(6)
(1)
Example of operaon inside
the ‘conguraon menu’.
1. The (<) key enters into the
‘conguraon menu’.
2. The (<) key enters into the
‘InP’ menu.
3. The (5) key moves through
the menu opons.
4. The (<) key selects the de-
sired range and returns to
the ‘InP’ menu.
5. The (3) key leaves the ac-
tual menu level and moves
to the previous menu level.
6. The (3) key leaves the ‘con-
guraon menu’. Changes
are applied and saved at
this moment.
Figure 5 - Example of operaon inside the ‘conguraon menu’

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
17
1.21.2 Inial set-up
To congure the inial set up of the instrument, select the
working mode and congure the bus parameters.
The instrument has 2 working modes named ‘Full slave’ and
‘Process slave’. In both modes, the reading value is received
from the communicaons bus. The dierences between
modes are related to how the alarms are controlled.
At the ‘Working mode’ (‘ModE’) parameter, select one of the
working modes.
• select ‘Full slave’ to control the alarms directly from the
communicaons bus, by wring to the internal instrument
registers. Analog outputs and other output and control
modules are controlled locally from the instrument.
• select ‘Process slave’ to control the alarms locally from
the instrument, by manually conguring the setpoint and
other alarm parameters. Analog outputs and other output
and control modules are controlled locally from the instru-
ment.
Conguraon menus for both modes are slightly dierent.
The following secons will menon when a parameter applies
only to one of the modes.
Press ‘SQ’ (<) for 1 second to access the ‘conguraon
menu’. For a descripon on how to operate inside the menus
see secon 1.21.1. For a full vision of the ‘conguraon menu’
structure see secon 1.22.
Working mode
‘Process slave’ mode
‘Full slave’ mode
Speed
(kbps)
from 38.4 Kbps
...
...
to 600 bps
Bus
conguraon
8 bits, no parity, 1 stop
Format
8 bits, even parity, 1 stop
8 bits, odd
parity
, 1
stop
8 bits, no parity, 2 stop
At the ‘Bus conguraon’ (‘buS’) menu congure the bus
speed and the bus data format.
• at the ‘Speed’ (‘bAud’) parameter select the bus speed, in
kbps.
• at the ‘Format’ (‘bItS’) parameter select the bus format be-
tween ‘8n1’, 8e1’, ‘8o1’ and ‘8n2’.

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
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As a standard, Modbus RTU protocol is designed to work with
registers of 16 bits. This allows to work with numerical values
between 32767 and -32767. In order to work with numerical
values up to 999999 and -199999, larger register of 32 bits
are needed (see secon 1.21.5). A 32 bits register is read and
wrien as if it was composed of 2 registers of 16 bits.
To write on 32 bits registers use funcon 16 ‘Write mulple
registers’ and to read on 32 bits registers use funcon 3
‘Read registers’. Working with 32 bits registers has the fol-
lowing limitaons:
• registers of 32 bits (2 registers of 16 bits) must be writ-
ten or read using the same single funcon. It is not al-
lowed to write 16 bits with a funcon and then write the
following 16 bits in the next funcon.
• in case of wring (or reading) only a part of a 32 bits
register (only rst 16 bits or last 16 bits) the instrument
will discard the write (or read) funcon. Instrument will
not transmit error code.
Available ‘funcons’, ‘registers’ and ‘coils’ for each mode are
explained at secons 1.17, 1.18, 1.19 and 1.20.
In ‘Full slave’ mode, the ‘master’ controls the acvaon and
deacvaon of each individual alarm in the ‘slave’ instru-
ment, by sending write funcons to the appropriate regis-
ters or coils. By default, alarm control is performed by writ-
ing to coils. To switch to alarm control by wring to registers,
congure the menu ‘Alarm control’ (‘AL.ct’).
Alarm control by coil or register is selectable but only one
type of control can be acve.
Available ‘funcons’, ‘registers’ and ‘coils’ for each mode are
explained at secons 1.17, 1.18, 1.19 and 1.20.
The ‘watchdog’ funcon acvates an error state in case of
loss of communicaon with the ‘master’. To congure the
‘watchdog’ indicate the maximum me accepted to wait be-
tween two frames received. If the congured me is exceed-
ed, the instrument acvated the ‘watchdog error’. When a
correct frame is received, the ‘watchdog’ mer is reset.
Frames that can reset the ‘watchdog’ mer are those ad-
dressed to the ‘slave’ instrument. These frames must con-
form to the Modbus RTU protocol and have a correct CRC.
If the funcon or register or coil indicated in the frame is not
correct, the ‘slave’ instrument will sll reset the ‘watchdog’
mer. It will also reply with the corresponding error mes-
sage.
The internal alarms of the instrument can be associated to
the ‘watchdog’. In case of ‘watchdog’ acvaon, the associ-
ated alarm will also acvate (see secon 1.21.8).
Display can also be congured to show an error message in
case of ‘watchdog’ error. It can be congured for ashing,
dash (‘------’) or to show message ‘Err.W’.
The instrument can be assigned any address between 1 and
247.
1.21.3 Addresses
1.21.4 ‘Watchdog’ funcon
1.21.5 16 bits or 32 bits registers
1.21.6 Alarm control : registers and ‘coils’

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
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At the ‘Conguraon’ (‘cnF’) menu, congure the parame-
ters associated to the instrument funcon, such as the local
address, the ‘watchdog’ me and error behavior, the data
length and the alarm control.
• at the ‘Local address’ (‘Addr’) parameter congure the
local address of the instrument. Values from 1 to 247.
• at the ‘Watchdog’ (‘W.doG’) parameter congure the
maximum waing me between frames, in seconds. Select
‘0’ to disable the ‘watchdog’. Maximum value 120 seconds.
In case of watchdog error acvaon, the funcon ‘on.Er’
will be triggered (see secon 1.21.4).
• at the ‘On error’ (‘on.Er’) parameter congure the acon
in case of watchdog error:
- select ‘Flash’ (‘FLSh’) to acvate the ash on display
- select ‘Dashes’ (‘dASh’) to acvate dashes (‘----’) on dis-
play
- select ‘Watchdog error’ (‘Err.W’) to acvate the mes-
sage ‘Err.W’ on display.
- select ‘do nothing’ (‘nonE’) to perform no acon.
• at the ‘Data lengh’ (‘dAtA’) parameter congure the in-
strument to work with 16 bit or 32 bit registers. By default,
it works with 16 bit registers (see secon 1.21.5).
• the ‘Alarm control’ (‘AL.ct’) parameter applies only
in ‘Full Slave’ mode. Select ‘coIL’ or ‘hoLd’ to congure
alarm control by wring to coils or to registers (see secon
1.21.6).
Conguraon
1 to 247
Local address
Watchdog
Waing me
On error
Flash
Dashes (----)
Do nothing
Watchdog error
Data length
16 bits
32 bits
Alarm control By registers
By ‘coils’
1.21.7 Conguraon menu

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
20
1.21.8 Alarms
The instrument manages 3 independent internal alarms,
each one controlling the acvaon of an oponal relay,
transistor or control SSR output. Oponal modules (see
secon 2) are installed at the free slots inside the instru-
ment
(see secon 1.7)
. B24 and B44 formats have 2 free
slots for output and control modules, while B26 and B46
formats have 3 free slots for output and control modules.
The instrument has 3 front leds that reect the state of
the 3 internal alarms. These leds are only for local help
during installaon, as they are not appropriate for long
distance reading.
Each alarm controls the acvaon of the relay, transis-
tor or control SSR installed on its associated slot, and the
front led.
• Alarms in ‘Full slave’ mode
In ‘Full slave’ mode, the alarms are controlled through the
bus. By default the control is performed by wring to the
‘coils’. to acvate control by wring to ‘registers’ see sec-
on
(see secon 1.21.6)
.
In ‘Full slave’ mode an alarm can be associated to the
watchdog. This alarm will acvate when the watchdog er-
ror acvates
(see secon 1.21.4)
. This funcon allows to
acvate a relay to inform about loss of communicaon.
• Alarms in ‘Process slave’ mode
In ‘Process slave’ mode, the alarms are controlled locally
at the instrument, and the operator must manually con-
gure them.
Each alarm has several parameters for conguraon,
starng with the usual setpoint, hysteresis and maximum
(alarm acve when reading is higher than setpoint) or
minimum (alarm acve when reading is lower than mini-
mum) alarm types
(see Figure 6)
.
Each alarm can congure independent acvaon and
deacvaon delays. These delays aect the alarm as a
whole, and the delay will aect the front led and the as-
sociated relay.
Conguring a second setpoint creates ‘windowed alarms’.
The windowed alarm controls with a single relay output
if the reading is inside or outside the values dened
(see
Figure 7)
.
Acvate the ‘inverted relay’ funcon to invert the acva-
on logic of the associated relay.
Acvate the ‘locked alarms’ funcon will force the opera-
tor to interact with the instrument when an alarm has
been acvated. Once acvated, the alarm will remain
locked at acve state, even if the reading returns to a val-
ue below setpoint, unl the operator manually unlocks
the alarms pressing the front key ‘LE’ (or the remote key
‘LE’, see secon 3.1).
Reading
t
setpoint
hysteresis
Alarm as maximum, no
hysteresis, no delays
on
o
acvaon
delay
on
o
deacvaon
delay
Alarm as maximum,
hysteresis and delays
on
o
Alarm as minimum, no
hysteresis, no delays
t
t
t
Figure 6 - Examples of alarm with 1 setpoint
Reading
t
Setpoint 2
Setpoint 1
Alarm as minimum
, with
double setpoint, no hyster-
esis, no delays
on
o
t
Figure 7 - Example of alarm with 2 setpoints
This manual suits for next models
1
Table of contents