AMALGAMATED INSTRUMENT PM4-IVT Guide

Model PM4-IVT
Process Rate/Total Monitor
Panel Mount Display/Controller
Operation and Instruction Manual
AMALGAMATED INSTRUMENT CO ABN: 80 619 963 692
Unit 5, 28 Leighton Place Hornsby Telephone: [phone] e-mail: [email protected]
NSW 2077 Australia Facsimile: [phone] Internet: www.aicpl.com.au

Table of Contents
1 Introduction 3
2 Mechanical Installation 4
3 Electrical installation 5
4 Function tables - summary of setup functions 11
5 Explanation of functions 16
6 Calibration 40
7 Specifications 44
8 Guarantee and service 45
2 of 45 PM4IVTMAN-2.3-0

1 Introduction
1.1 General description
This manual contains information for the installation and operation of the PM4-IVT rate/total
monitor. The PM4-IVT is a general purpose instrument which may be configured to accept an
input signal of ±2mA, ±20mA, 4 to 20mA, ±100mV, ±1V, ±10V, ±100VDC or 3 wire slidewire
(0-1kΩ to 0-1MΩ).
The display can toggled between rate and total display via the ^or vpushbuttons or via a
remote switch input. The total can be reset by programming either the Pbutton (if fitted on
display type used) or the remote input (terminals 7 and 8) to clear the total, see P.but and R.INP
functions. Alternatively the total can be reset at the CLr totI function. Unless the display
has been programmed to automatically reset to zero (see totI RAP.F function) at full display
scale reading e.g. 99999 the display will show the message -or- when the total is too large to
display, when this message is seen the total will need to be reset before totalising operations can
be resumed. The instrument may be calibrated to display the input in engineering units.
The PM4 series of Panel Mount Monitors are designed for high reliability in industrial applica-
tions. The high brightness LED display provides good visibility even in areas with high ambient
light levels. The high contrast LCD displays provide good visibility and are ideal for battery
powered applications. Full electrical isolation between power supply, input voltage or current and
retransmission output is provided by the PM4, thereby eliminating grounding and common voltage
problems. This isolation feature makes the PM4 ideal for interfacing to computers, PLCs and
other data acquisition devices. Unless otherwise specified at the time of order, your PM4 has been
factory set to a standard configuration. The PM4 series instruments can be configuration and
calibrated easily by the user. Initial changes may require dismantling the instrument to alter PCB
links, other changes are made by push button functions.
1.2 Standard outputs
•A standard inbuilt relay provides an alarm or on/off control function.
•A non isolated transmitter supply of approx. 18VDC (25mA max.) regulated is provided.
1.3 Output options
•1, 3 or 6 extra relays
•Isolated analog retransmission (single or dual analog outputs) configurable for 4–20mA, 0–1V
or 0–10V, configurable for retransmission or PI control
• ±12VDC (24V) isolated transmitter supply/excitation voltage (25mA max.). Not to be used
at the same time as the standard 18VDC unregulated transmitter supply
•Isolated RS485 or RS232 serial communications (ASCII or Modbus RTU)
•Isolated Digital output - binary or BCD up to 16 bit, NPN or PNP output types available
•Isolated Optional outputs are available in certain combinations e.g. Extra relay plus RS232
PM4IVTMAN-2.3-0 3 of 45

2 Mechanical Installation
Choose a mounting position as far away as possible from sources of electrical noise such as motors,
generators, fluorescent lights, high voltage cables/bus bars etc. An IP65 or IP67 access cover which
may be installed on the panel and surrounds is available as an option to be used when mounting the
instrument in damp/dusty positions. A wall mount case is available, as an option, for situations
in which panel mounting is either not available or not appropriate. A portable carry case is also
available, as an option, for panel mount instruments.
Prepare a panel cut out of 45mm x 92mm +1 mm / – 0 mm (see diagram below). Insert the
instrument into the cut out from the front of the panel. From the rear of the instrument fit the
two mounting brackets into the recess provided (see diagram below). Whilst holding the bracket
in place, tighten the securing screws being careful not to over-tighten, as this may damage the
instrument. Hint: use the elastic band provided to hold the mounting bracket in place whilst
tightening securing screws.
92mm
45mm PANEL CUT OUT 92mm
45mm
PANEL
CUT
OUT
115mm
104mm
53mm
44mm
96mm
9mm
9.5mm
max
48mm
91mm
111mm
10mm
Mounting bracket
(2 off)
Horizontal mounting
Vertical mounting
(bar graph displays)
4 of 45 PM4IVTMAN-2.3-0

3 Electrical installation
3.1 Electrical installation
The PM4 Panel Meter is designed for continuous operation and no power switch is fitted to the
unit. It is recommended that an external switch and fuse be provided to allow the unit to be
removed for servicing.
The plug in, screw type, terminal blocks allow for wires of up to 2.5mm2to be fitted. Connect the
wires to the appropriate terminals as indicated below. Refer to connection details provided in this
chapter to confirm proper selection of voltage, polarity and input type before applying power to
the instrument.
When power is applied the instrument will cycle through a display sequence indicating the software
version and other status information, this indicates that the instrument is functioning. Acknowl-
edgement of correct operation may be obtained by applying an appropriate input to the instrument
and observing the reading. The use of screened cable is recommended for signal inputs.
For connection details of optional outputs refer to the separate ”PM4 Panel Meter Optional Output
Addendum” booklet supplied when options are fitted.
MAINS EARTH
AC ACTIVE
AC NEUTRAL
COM
RELAY 1
N/O
EXT-IN
TRANSMITTER
SUPPLY +
(18VDC REGULATED,
25mA MAXIMUM)
GND INPUT -
INPUT +
TYPICAL TOP CONNECTOR
LAYOUT FOR OPTION BOARD
(DC+)
(DC-)
SETUP
PUSHBUTTONS
AB HC D EF J K
1 2 3 4 5 6 7 8 9 10 11 F^v
PM4IVTMAN-2.3-0 5 of 45

3.2 Electrical connection examples
If output options are fitted refer to the ”PM4 Panel Meter Optional Output Addendum” booklet
for connection details.
AC power connections - supply type is factory configured, check before connecting
1 2 3 4 5 6 7 8 9 10 11
Case earth
Neutral
Active
DC power connections (12 to 48VDC) - supply type is factory configured, check before connecting
2 wire 4-20mA powered from non isolated regulated 18V supply (25mA maximum)
1 2 3 4 5 6 7 8 9 10 11
2 WIRE
4-20mA
SENSOR
+
-
4-20mA
2 wire 4-20mA externally powered sensor
1 2 3 4 5 6 7 8 9 10 11
2 WIRE
4-20mA
SENSOR
External Power
Supply
+
+
-
-
4-20mA
6 of 45 PM4IVTMAN-2.3-0

3 wire 4-20mA externally powered sensor
1 2 3 4 5 6 7 8 9 10 11
3 WIRE
4-20mA
SENSOR
External Power
Supply
+
+
-
-
4-20mA
4 wire 4-20mA externally powered sensor
1 2 3 4 5 6 7 8 9 10 11
4 WIRE
4-20mA
SENSOR
External Power
Supply
+
+
-
-
4-20mA
3 wire 4-20mA powered from non isolated regulated 18V supply (25mA maximum)
1 2 3 4 5 6 7 8 9 10 11
3 WIRE
4-20mA
SENSOR
Signal/
output
+V
-
4-20mA
2 wire 4-20mA powered from optional isolated regulated 24V (±12V) supply (25mA maximum)
AB HC D E F J K
1 2 3 4 5 6 7 8 9 10 11
SENSOR
Use D & F for 24VDC
Use E & F for 12VDC
Isolated DC output
(optional)
Wire link
+
-
-
+
4-20mA
DC voltage input
1 2 3 4 5 6 7 8 9 10 11
SENSOR/
INPUT
DEVICE
+
-
PM4IVTMAN-2.3-0 7 of 45

Slidewire input
1 2 3 4 5 6 7 8 9 10 11 Note: Links LK7 &
LK8 Must be set
to SLIDE WIRE for
Slide Wire input
all other links should
be out.
Remote input
1 2 3 4 5 6 7 8 9 10 11
Momentary or
latching action
switch
8 of 45 PM4IVTMAN-2.3-0

3.3 Input Output Configuration
If you need to alter the input or output configuration link settings proceed as follows:
Remove earth screw
which passes through the
case then slide out
the printed circuit board
1. Remove the plug in terminals
from the rear of the instrument
2. Remove the 4 x self tapping screws from
the back cover then remove the back cover
by pulling it away from the instrument
3. Remove the earth screw which passes
through the underside of the case then
slide out the board or boards
4. Configure the PCB links as requred, see appropriate chapter
5. Slide PCB back into case
6. Replace the earth screw which passes through the case
7. Refit the back cover and fix with the self tapping screws
8. Plug the terminal strips back into the rear of the instrument
PM4IVTMAN-2.3-0 9 of 45

3.4 Input range link selection
Dismantle the instrument as described in section 3.3. Insert the links into the appropriate location
on the pin header to suit the range required.
LK1
LK6
LK7 LK8
EX
SLW
X10
100
10V
1V
4-20
mA
Transmitter
Supply Output
Selected
Slidewire
Excitation
Selected
LK7LK7 LK8LK8
EXEX
SLWSLW
LK1 LK1 LK1 LK1 LK1LK1
LK6 LK6 LK6 LK6 LK6LK6
X10 X10 X10 X10 X10X10
100 100 100 100 100100
10V 10V 10V 10V 10V10V
1V 1V 1V 1V 1V1V
4-20
mA
4-20
mA
4-20
mA
4-20
mA
4-20
mA
4-20
mA
±20mA or 4-20mA
input selected
±2mA
input selected
±100mV Input
Selected
±1V Input
Selected
±10V Input
Selected
±100V Input
Selected
Note: all other links should
be out when slidewire is
selected.
10 of 45 PM4IVTMAN-2.3-0

4 Function tables - summary of setup functions
Note: the order in which the functions appear on the display may not be exactly as shown below.
The availability and order of functions is determined by choice of function settings and options
fitted.
Functions in this first table are available in FUNC or CAL mode
Display Function Range Default Your
record
Ref/Page
AxPS Relay pass value Any display
value
OFF See
4.1
5.1 /18
AxPt Relay pass time 0.0 to 999.9 0.0 See
4.1
5.2 /18
AxLo Low setpoint value for
designated alarm relay x
Any display
value or OFF
OFF See
4.1
5.3 /18
AxHi High setpoint value for
designated alarm relay x
Any display
value or OFF
OFF See
4.1
5.4 /19
AxHY Hysteresis value for the
designated alarm relay x.
0to 9999 10 See
4.1
5.5 /20
Axtt Trip time delay for the
designated alarm relay x.
0to 9999 0 See
4.1
5.6 /20
Axrt Reset time delay for the
designated alarm relay x.
0to 9999 0 See
4.1
5.7 /21
Axn.o
or
Axn.c
Alarm relay xaction to
normally open (de-energised) or
normally closed (energised)
Axn.o or
Axn.c
Axn.o See
4.1
5.8 /21
AxSP
or
Axt1
etc.
Relay operation independent
setpoint or trailing setpoint
(∗Optional)
AxSP or
Axt1 etc.
AxSP See
4.1
5.9 /21
brGt Display brightness level 1to 15 15 5.10 /22
duLL Display remote brightness
switching
0to 15 1 5.11 /22
(∗Optional)—this function will only be accessible if the relevant option is fitted
PM4IVTMAN-2.3-0 11 of 45

Functions in this second table are available only in CAL mode or if ACCS is set to ALL
Display Function Range Default Your
record
Ref/Page
bAr_ Bargraph low value (seen only
on bargraph display
instruments)
Any display
value
05.12 /22
bAr~ Bargraph high value (seen only
on bargraph display
instruments)
Any display
value
1000 5.13 /23
bAr
tYPE
Bargraph type for instruments
with bargraph display (seen
only on bargraph display
instruments)
bAr,S.dot,
d.dot,
C.bAR or
r.dot
bAr 5.14 /23
dGOP Digital output option mode
(∗Optional)
bcd,b.SCL,
bin or bin2
bin2 5.15 /24
dG.OP Digital output option polarity
(∗Optional)
AIo or AHi AIo 5.16 /24
bcd
Strt
Digital output option BCD start
position (∗Optional)
0,1or 2 0 5.17 /24
diG_ Digital output option low value
(∗Optional)
Any display
value
05.18 /25
diG~ Digital output option high value
(∗Optional)
Any display
value
1000 5.19 /25
REC_ Analog output option low
display value (∗Optional)
Any display
value
05.20 /25
REC~ Analog output option high
display value (∗Optional)
Any display
value
1000 5.21 /25
REC_
Ch2
Second analog output option
low display value (∗Optional)
Any display
value
05.22 /26
REC~
Ch2
Second analog output option
high display value (∗Optional)
Any display
value
1000 5.23 /26
drnd Display rounding 1to 5000 1 5.24 /26
dCPt Decimal point 0,0.1 etc. 05.25 /26
FLtr Digital filter 0to 8 2 5.26 /27
rec
ctrI
Analog output PI control
(∗Optional)
on or OFF OFF 5.27 /27
CAL1 First live input calibration
scaling point
Any display
value
n/a 5.28 /27
CAL2 Second live input calibration
scaling point
Any display
value
n/a 5.29 /28
CAL
OFSt
Calibration offset Any display
value
n/a 5.30 /28
ZERO
RNGE
Zero range limit Any display
value or OFF
OFF 5.31 /28
(∗Optional)—this function will only be accessible if the relevant option is fitted
12 of 45 PM4IVTMAN-2.3-0

CAL
ZERO
Zero reference point for ZERO
RNGE operation
n/a n/a 5.32 /28
USER
En4
4mA input scale Any display
value
n/a 5.33 /28
USER
En20
20mA input scale Any display
value
n/a 5.34 /29
UCAL Uncalibrate n/a n/a 5.35 /29
Pbut Pbutton function (for
instruments with front P
button)
NONE, Hi,
Lo, HiLo,
ZERO, dISP,
or CLR.t
NONE 5.36 /29
R.INP Remote input (external input)
function
NONE,
P.HLd,
d.HLd, Hi,
Lo , HiLo,
ZERO,
SP.Ac,
No.Ac,
CAL.S,
duLL, dISP
or CLR.t
NONE 5.37 /29
ACCS Access mode OFF, EASY,
NONE or ALL
OFF 5.38 /31
SPAC Setpoint access mode
(∗Optional)
A1, A1-2 etc. A1 5.39 /31
SQrt Square root mode on or OFF OFF 5.40 /31
tOtI
dCPt
Total display decimal point
selection
0to number of
display digits
minus 1
05.41 /32
dISP
SCLE
Total display scaling factor Any display
value
15.42 /32
tOtI
SECS
Totaliser scaling factor Any display
value
60 5.43 /32
E.SCL Total exponent scaling factor 0to 9 0 5.44 /33
totI
NEG
Negative total select OFF or on OFF 5.45 /34
totI
RAP.F
Wrap around operation ZERO or
StOP
ZERO 5.46 /34
CLR
totI
Clear total n/a n/a 5.47 /34
dFIt
dISP
Default display RAtE or
tOtI
RAtE 5.48 /35
(∗Optional)—this function will only be accessible if the relevant option is fitted
PM4IVTMAN-2.3-0 13 of 45

Ax.rt,
Ax.tL
or
Ax.PS
Alarm relay 1 operation mode Ax.rt,Ax.tL
or Ax.PS
Ax.rt 5.49 /35
bAR Bargraph display operation
mode
rAtE or
totL
rAtE 5.50 /35
rEC Analog operation mode
(∗Optional)
LiuE, totL,
P.HLd,
d.HLd, Hi,
Lo or dISP
LiuE 5.51 /35
dG.OP Digital output operation mode
(∗Optional)
rAtE or
totL
rAtE 5.52 /36
Lo
dISP
Low overrange visual warning
limit value
Any display
value or OFF
OFF 5.53 /36
HIGH
dISP
High overrange visual warning
limit value
Any display
value or OFF
OFF 5.54 /36
dISP Display visual warning flashing
mode
FLSH or
-or-
FLSH 5.55 /37
bAUd
RAtE
Baud rate for serial
communications (∗Optional)
300, 600,
1200, 2400,
4800, 9600,
19.2 or 38.4
9600 5.56 /37
PrtY Parity for serial communications
(∗Optional)
NONE, EUEN
or odd
NONE 5.57 /37
O.Put Output for serial
communications (∗Optional)
dISP, Cont,
POLL,A.buS
or M.buS
Cont 5.58 /38
Addr Instrument address for serial
communications (∗Optional)
0to 31 0 5.59 /38
SERL Serial mode for serial
communications (∗Optional)
LiuE, totL,
P.HLd,
d.HLd, Hi,
Lo, HiLo or
both
LiuE 5.60 /38
(∗Optional)—this function will only be accessible if the relevant option is fitted
14 of 45 PM4IVTMAN-2.3-0

4.1 Relay table
Record your relay settings in the table below
Display Relay 1 Relay 2 Relay 3 Relay 4 Relay 5 Relay 6 Relay 7
AxPS
AxPt
AxLo
AxHi
AxHY
Axtt
Axrt
Axn.o or Axn.c
AxSP or Axt1 etc. n/a
Ax.rt,Ax.tL or Ax.PS
PM4IVTMAN-2.3-0 15 of 45

5 Explanation of functions
The PM4 setup and calibration functions are configured through a push button sequence. The
three push buttons located at the rear of the instrument (also at the front on some display options)
are used to alter settings. Two basic access modes are available:
FUNC mode (simple push button sequence) allows access to commonly set up functions such as
alarm setpoints.
CAL mode (power up sequence plus push button sequence) allows access to all functions including
calibration parameters.
Once CAL or FUNC mode has been entered you can step through the functions, by pressing and
releasing the Fpush button, until the required function is reached. Changes to functions are made
by pressing the or push button (in some cases both simultaneously) when the required function is
reached. See the flow chart example on the following page.
P F
P F P F
P F
P F
Entering ModeCAL Entering ModeFUNC
1. Remove power from
the instrument. Hold in the
button and reapply power.
The display will briefly indicate
as part of the
"wake up messages" when
the message is seen
you can release the
button. Move to step 2 below.
2. When the "wake up"
messages have finished
and the display has settled
down to its normal reading
press, then release the
button.
Move to step 3 below.
1. When the "wake up"
messages have finished
and the display has settled
down to its normal reading
press, then release the
button.
3. Within 2 seconds of
releasing the button
press, then release
the and buttons
together. The display will
now indicate followed
by the first function.
2. Within 2 seconds of
releasing the button
press, then release
the and buttons
together. The display will
now indicate followed
by the first function.
^
^
^^
FUNC
FUNC
F
F
F
FF
CAL
CAL
Note: If step 1 above has been completed then the
instrument will remain in this mode state until
power is removed. i.e. there is no need to repeat step 1
when accessing function unless power has been removed.
CAL
No special power up procedure
is required to enter mode.FUNC
16 of 45 PM4IVTMAN-2.3-0

Example: Entering FUNC mode to change alarm 1 high function A1Hi from OFF to 100
F U N C
F U N C End
A1Hi OFF
100
Press & release
Press & release Press & release
Press & release
Press & release F
^until
FP For until
Funtil
then press ^v
Example: Entering CAL mode to change decimal point function dCPt from 0to 0.02
F U N C
F U N C End
dCPt
CAL
0
.0 0 2
Press & release
Press & release Press & release
Press & release
Press & hold Release
Hold
Press & release F
^until
FP For until
Funtil
FF
Funtil
then press ^v
Switch off
instrument
Switch on
instrument
Easy alarm relay adjustment access facility
The display has an easy alarm access facility which allows access to the alarm setpoints simply by
pressing the Fbutton at the front or rear of the instrument. The first setpoint will then appear
and changes to this setpoint may be made to this setpoint via the ^or vbuttons. Press the
Fbutton to accept any changes or to move on to the next setpoint. Note: this easy access also
functions in the same manner for the PI control setpoint (relay and/or analog PI output) if PI
control is available. The instrument must be set in the manner described below to allow the easy
access facility to work:
1. The R.INP function must be set to SPAC or the ACCS function must be set to EASY.
2. At least one alarm must have a setpoint, nothing will happen if all the alarm setpoints are
set to OFF.
3. The SPAC function must be set to allow access to the relays required e.g. if set to A1-2
then the easy access will work only with alarm relays 1 and 2 even if more relays are fitted.
4. The instrument must be in normal measure mode i.e. if the instrument is powered up so that
it is in CAL mode then the easy access will not function. If in doubt remove power from the
instrument, wait for a few seconds then apply power again.
5. If the easy access facility is used then the only way to view or alter any other function
settings is to power up via CAL mode i.e. there is no entry to FUNC mode functions unless
the instrument is powered up in CAL mode.
PM4IVTMAN-2.3-0 17 of 45

Explanation of Functions
5.1 Relay pass value
Display: AxPS
Range: Any display value
Default Value: OFF
Alarm relay pass value - only seen when AxPS is selected at the Axrt/AxtL/AxPS function.
Displays and sets the chosen alarm relay (A1Pt,A2Pt etc.) pass time in seconds. The alarm
relay will activate at multiples of the pass value e.g. if A1PS is set to 50 then relay 1 will activate
at a total display value of 50,100,150 etc. The time for which the relay remains activated at
each pass value is set via the AxPt function which follows. The pass value may be set anywhere
in the display range of the instrument, positive or negative. The pass value can be set to OFF
(disabled) by pressing the ^and vbuttons together.
5.2 Relay pass time
Display: AxPt
Range: 0.0 to 999.9
Default Value: 0.0
Alarm relay pass time - only seen when AxPS selected at the Axrt/AxtL/AxPS function.
Displays and sets the chosen alarm relay (A1Pt,A2Pt etc.) pass time in seconds. The value set
is the time for which the relay will remain energised when activated at a pass value. e.g. if set to
2.0 with a A1PS value of 50 then the relay will remain energised for 2.0 seconds every time the
display passes a multiple of 50. Note: If the pass time exceeds the time taken to reach consecutive
pass values then the instrument will “store” any relay operations it does not have time to activate
and will perform these activations when the total display update rate allows. For this reason the
relay may be seen to activate repeatedly for a period after the total update rate has slowed down
or stopped.
5.3 Alarm relay low setpoint
Display: AxLo
Range: Any display value or OFF
Default Value: OFF
Displays and sets the low setpoint value for the designated alarm relay x. Note xwill be replaced
by the relay number when displayed e.g. A1Lo for relay 1. Use this low setpoint function if a
relay operation is required when the display value becomes equal to or less than the low setpoint
value. To set a low alarm value go to the AxLo function and use the ^or vpush buttons to set
the value required then press Fto accept this value. The low alarm setpoint may be disabled by
pressing the ^and vpush buttons simultaneously. When the alarm is disabled the display will
indicate OFF. If the relay is allocated both a low and high setpoint then the relay will activate
when the value displayed moves outside the band set by the low and high setpoints. The value at
which the relay will reset is controlled by the AxHY function.
Example:
18 of 45 PM4IVTMAN-2.3-0

If A1Lo is set to 10 then relay 1 will activate when the display value is 10 or less.
Display Value
Time
A Lox
A HYxvalue
A Lo
A HY
x
x
plus
Relay
activates
at this value
or below
Relay
resets
above this
value
Alarm low operation with hysteresis
5.4 Alarm relay high setpoint
Display: AxHi
Range: Any display value or OFF
Default Value: OFF
Displays and sets the high setpoint value for the designated alarm relay x. Note xwill be replaced
by the relay number when displayed e.g. A1Hi for relay 1. Use this high setpoint function if a
relay operation is required when the display value becomes equal to or more than the low setpoint
value. To set a high alarm value go to the AxHi function and use the ^or vpush buttons to
set the value required then press Fto accept this value. The high alarm setpoint may be disabled
by pressing the ^and vpush buttons simultaneously. When the alarm is disabled the display
will indicate OFF. If the relay is allocated both a low and high setpoint then the relay will activate
when the value displayed moves outside the band set by the low and high setpoints. The value at
which the relay will reset is controlled by the AxHY function.
Example:
If A1Hi is set to 100 then relay 1 will activate when the display value is 100 or higher.
Display Value
Time
A Hix
A Hi
A HY
x
x
minus Relay
activates
at this value
or above Relay
resets
below this
value
A HYxvalue
Alarm high operation with hysteresis
PM4IVTMAN-2.3-0 19 of 45

5.5 Alarm relay hysteresis (deadband)
Display: AxHY
Range: 0to 9999
Default Value: 10
Displays and sets the alarm relay hysteresis limit for the designated relay x. Note xwill be replaced
by the relay number when displayed e.g. A1HY for relay 1. To set a relay hysteresis value go to the
AxHY function and use the ^or vpush buttons to set the value required then press Fto accept
this value. The hysteresis value is common to both high and low setpoint values. The hysteresis
value may be used to prevent too frequent operation of the relay when the measured value is rising
and falling around setpoint value. e.g. if A1HY is set to zero the alarm will activate when the
display value reaches the alarm setpoint (for high alarm) and will reset when the display value falls
below the setpoint, this can result in repeated on/off switching of the relay at around the setpoint
value.
The hysteresis setting operates as follows: In the high alarm mode, once the alarm is activated
the input must fall below the setpoint value minus the hysteresis value to reset the alarm. e.g. if
A1Hi is set to 50.0 and A1Hy is set to 3.0 then the setpoint output relay will activate once the
display value goes to 50.0 or above and will reset when the display value goes below 47.0 i.e. at
46.9 or below. In the low alarm mode, once the alarm is activated the input must rise above the
setpoint value plus the hysteresis value to reset the alarm. e.g. if A1Lo is to 20.0 and A1Hy
is set to 10.0 then the alarm output relay will activate when the display value falls to 20.0 or
below and will reset when the display value goes above 30.0 i.e at 30.1 or above. The hysteresis
units are expressed in displayed engineering units.
Example: If A1Hi is set to 100 and A1HY is set to 10 then relay 1 will activate when the
display value is 100 or higher and will reset at a display value of 89 or lower.
5.6 Alarm relay trip time
Display: Axtt
Range: 0to 9999
Default Value: 0
Displays and sets the alarm trip time in seconds. The trip time is common for both alarm high and
low setpoint values. The trip time provides a time delay before the alarm relay will activate when
an alarm condition is present. The alarm condition must be present continuously for the whole trip
time period before the alarm will activate. If the input moves out of alarm condition during this
period the timer will reset and the full time delay will be restored. This trip time delay is useful
for preventing an alarm trip due to short non critical deviations from setpoint. The trip time is
selectable over 0to 9999 seconds. To set a trip time value go to the Axtt function and use the
^or vpush buttons to set the value required then press Fto accept this value.
Example: If A1tt is set to 5seconds then the display must indicate an alarm value for a full 5
seconds before relay 1 will activate.
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