Novus DigiRail-2A Use and care manual

NOVUS AUTOMATION 1/5
DigiRail-2A
Universal Analog Input Modules
COMMUNICATION MANUAL
INTRODUCTION
The DigiRail-2A is provided with RS485 two wire serial communications, operating as slave in the Modbus RTU
protocol. The entire equipment configuration, as well as reading of the input data, is performed through serial
communication.
This manual provides the information necessary for reading the data from the input channels without using the software
DigiConfig. In order to assure the correct configuration of DigiRail, always use the DigiConfig software. After being
configured, the data of its inputs and/or outputs can be accessed by any other software having Modbus RTU
communication capacity.
For further details regarding the implementation of a network of devices please refer to the document Basic Concepts of
RS485 and RS422, available the website www.novusautomation.com, for download.
MODBUS ADDRESS ASSIGNMENT SYSTEMATICS
The DigiRail equipment does not have keys for determination of the Modbus communication address. This must be
determined by using the communication in the Modbus protocol itself. This will require that the address of the device to
be configured is known, this being possible by two different means:
•If the equipment is a new one, it will show the configuration as set by the factory: Address=247, Baud rate=1200,
Parity Even, 1 Stop Bit.
•If the equipment has already been used and you do not know its address and/or other communication parameters,
press the RCom button on your front panel. It will enter the diagnostics mode during 1 minute, assuming the following
communication parameters: Address=246, Baud rate=1200, parity even, 1 stop bit.
The DigiConfig software configurator is provided with a function of searching the network for temporary devices, exactly
the devices in the previous conditions. Once having been localized, the address and the other communication
parameters can be changed according to the necessity of the application.
The communication parameters in the two previous conditions are not very common in Modbus networks, and they may
probably cause no conflicts with other equipment of the network. Obviously only one DigiRail in the network can be in
each of the previous conditions so that the communication with the configurator DigiConfig is possible. If several new
DigiRail are to be included in a network, they must be inserted individually. Only after changing the communication
parameters for the definitive values, the next new DigiRail can be inserted. In an already existing network, only one
DigiRail at a time can be set in diagnostics mode in order to be detected by the DigiConfig.
It is important to emphasize that the DigiConfig software acts as a master in the Modbus network. Its utilization requires
that the original master of the network (SCADA software, for instance) be disconnected during its use. For further details
please refer to the on-line Help of the DigiConfig.
MODBUS COMMANDS
The Modbus RTU commands (functions) listed below are implemented. For further information with respect to each one
of these commands and the Modbus protocol in general, please access the website:
http://www.modbus.org
READ INPUT REGISTERS - 04H
This command can be used for reading the current value of one or several input channels, according to the table below.
Address Description
0 PV of Channel 1 in percentage. Range from 0 to 62000.
1 PV of Channel 2 in percentage. Range from 0 to 62000.
2 – 4 Reserved
5
PV of Channel 1 in engineering unit.
Range: defined by the limits of the temperature sensor, or by the indication limits as
defined by the parameters 42 and 43 of the Holding Registers.

DigiRail-2A
NOVUS AUTOMATION 2/5
Address Description
6
PV of Channel 2 in engineering unit.
Range: defined by the limits of the temperature sensor, or by the indication limits as
defined by the parameters 44 and 45 of the Holding Registers.
7-9
Reserved
The specified addresses correspond to the low level physical addresses, where zero (0) corresponds to the address of
PLC 30001.
READ HOLDING REGISTERS – 03H
This command can be used for reading one or several holding registers, according to the table in the chapter apart.
WRITE SINGLE REGISTER – 06H
This command can be used for writing in a holding register, according to the table in the chapter apart.
TABLE OF HOLDING REGISTERS
The specified addresses correspond to the low level physical addresses, where zero (0) corresponds to the address of
PLC 40001. The columns minimum and maximum contain the range of values valid for each parameter. The column R/W
indicates if the parameter is for writing and reading (R/W) or for reading (R) only.
Address Description SuperView Mnemonic Minimum Maximum R/W
0 Series number (word high) - 0 65535 R
1 Series number (word low)
-
0 65535 R
2 Baud-rate - 0 7 R/W
3 Modbus Address
-
1 247 R/W
4 Parity - 0 2 R/W
5 Firmware version
-
0 999 R
6 Analog input filter - 0 20 R/W
7 Status flags of the input channels
InSts
0 65535 R
8 Reserved
-
0 0 R
9 PV of channel 1 in percentage PVPer1 0 62000 R
10 PV of channel 2 in percentage
PVPer2
0 62000 R
11-13 Reserved - 0 0 R
14 PV of channel 1 in engineering unit
PVEng1
-31000 31000 R
15 PV of channel 2 in engineering unit PVEng2 -31000 31000 R
16-20 Reserved
-
0 0 R
21 Input type of channel 1 In1Type -1 21 R/W
22 Input type of channel 2
In2Type
-1 21 R/W
23-25 Reserved - 0 0 R
26 Measuring unit of channel 1 - 0 1 R/W
27 Measuring unit of channel 2
-
0 1 R/W
28-30 Reserved - 0 0 R
31 User offset of channel 1
Ofs1
-16000 16000 R/W
32 User offset of channel 2 Ofs2 -16000 16000 R/W
33-35 Reserved
-
0 0 R
36 Square root fitness for channel 1 - 0 1 R/W
37 Square root fitness for channel 2
-
0 1 R/W
38-40 Reserved - 0 0 R
41 Lower indication limit of channel 1 when input type is linear
In1LL
-31000 31000 R/W
42 Upper indication limit of channel 1 when input type is linear
In1HL
-31000 31000 R/W
43 Lower indication limit of channel 2 when input type is linear In2LL -31000 31000 R/W
44 Upper indication limit of channel 2 when input type is linear
In2HL
-31000 31000 R/W
45-50 Reserved - 0 0 R
51 Lower indication limit of channel 1
-
-31000 31000 R
52 Upper indication limit of channel 1 - -31000 31000 R
53 Lower indication limit of channel 2
-
-31000 31000 R
54 Upper indication limit of channel 2 - -31000 31000 R

DigiRail-2A
NOVUS AUTOMATION 3/5
Address Description SuperView Mnemonic Minimum Maximum R/W
55-60 Reserved
-
0 0 R
61 Diagnostic state timer (in tenths of seconds) - 0 600 R/W
62 DigiRail model
-
0 4 R
63-125 Reserved - 0 0 R
126 Device tag - characters 1 and 2
-
0 65535 R/W
127 Device tag - characters 3 and 4 - 0 65535 R/W
128 Device tag - characters 5 and 6
-
0 65535 R/W
129 Device tag - characters 7 and 8
-
0 65535 R/W
130 Device tag - characters 9 and 10 - 0 65535 R/W
131 Channel 1 tag - characters 1 and 2
-
0 65535 R/W
132 Channel 1 tag - characters 3 and 4 - 0 65535 R/W
133 Channel 1 tag - characters 5 and 6
-
0 65535 R/W
134 Channel 1 tag - characters 7 and 8 - 0 65535 R/W
135 Channel 1 tag - characters 9 and 10
-
0 65535 R/W
136 Channel 2 tag - characters 1 and 2 - 0 65535 R/W
137 Channel 2 tag - characters 3 and 4
-
0 65535 R/W
138 Channel 2 tag - characters 5 and 6 - 0 65535 R/W
139 Channel 2 tag - characters 7 and 8
-
0 65535 R/W
140 Channel 2 tag - characters 9 and 10
-
0 65535 R/W
141 Tag of the channel 1 unit - characters 1 and 2 - 0 65535 R/W
142 Tag of the channel 1 unit - characters 3 and 4
-
0 65535 R/W
143 Tag of the channel 1 unit - characters 5 and 6 - 0 65535 R/W
144 Tag of the channel 1 unit - characters 7 and 8
-
0 65535 R/W
145 Tag of the channel 1 unit - characters 9 and 10 - 0 65535 R/W
146 Tag of the channel 1 unit - characters 1 and 2
-
0 65535 R/W
147 Tag of the channel 2 unit - characters 3 and 4 - 0 65535 R/W
148 Tag of the channel 2 unit - characters 5 and 6
-
0 65535 R/W
149 Tag of the channel 2 unit - characters 7 and 8 - 0 65535 R/W
150 Tag of the channel 2 unit - characters 9 and 10 - 0 65535 R/W
DETAILS OF SOME REGISTERS
REGISTER 2 – BAUD RATE
Code of speed used in Modbus communication.
Code
Baud rate
0
1.200
1
2.400
2
4.800
3
9.600
4
19.200
5
38.400
6
57.600
7
115.200
REGISTER 3 – MODBUS ADDRESS
Address of the device in the Modbus network. Valid values: from 1 to 247. We recommend using the lower addresses for
the equipment.
REGISTER 4 – PARITY
Code of the parity used in Modbus communication.
Code
Parity
0
No parity
1
Odd
2
Even

DigiRail-2A
NOVUS AUTOMATION 4/5
REGISTER 5 – FIRMWARE VERSION
Indicates the firmware version of the equipment, according to the examples below:
If the version is "1.00", the value "100" will be read. If the version is "2.04", the value "204" will be read.
REGISTER 6 – ANALOG INPUT FILTER
In order to reduce the effect of high frequency external interferences on the measurements performed by the equipment,
caused by electromagnetic noise existing in the environment of its installation, the signals read from the sensors are
internally filtered. When choosing a low value for the filter, rough measure variations may be possible. If there is much
noise in the environment where the sensors are installed, a higher value should be chosen for filtering rough measure
variations.
REGISTER 7 – STATUS FLAGS OF THE INPUT CHANNELS
Will inform errors and special conditions in processing the input channels through setting of their bits.
Bit
Information
0
Error at the conversion/processing of the channel 1 sensor
1
Error at the conversion/processing of the Pt100 excitation cable of channel 1
2
Underflow at channel 1
3
Overflow at channel 1
4
Indicates the unit used at channel 1
5
Not used
6
Not used
7
Not used
8
Error at the conversion/processing of the channel 2 sensor
9
Error at the conversion/processing of the Pt100 excitation cable of channel 2
10
Underflow at channel 2
11
Overflow at channel 2
12
Indicates the unit used at channel 2
13
Not used
14
Not used
15
Not used
REGISTERS 9 AND 10 – PV OF THE CHANNELS IN PERCENTAGE
Will inform the value of the channels in a linear scale between 0 and 62000, before transforming in engineering unit.
REGISTERS 14 AND 15 – PV OF THE CHANNELS IN ENGINEERING UNITS
Will inform the value of the channels in the configured engineering unit.
REGISTERS 21 AND 22 – CHANNELS INPUT TYPE
Will define the input type configured for the channel, according to the table below.
Configuration
Sensor
Range
-1
DISABLED
0
TC J
-130 a 940
1
TC K
-200 a 1370
2
TC T
-200 a 400
3
TC E
-100 a 720
4
TC N
-200 a 1300
5 TC R 0 a 1760
6
TC S
0 a 1760
7 TC B 500 1800
8
Pt100
-200 a 650
9
50 mV
0 to 62000 (-31000 to 31000)
10
20 mV
0 to 62000 (-31000 to 31000)
11
-10 to 20 mV
0 to 62000 (-31000 to 31000)
12
5 V
0 to 62000 (-31000 to 31000)
13
10 V
0 to 62000 (-31000 to 31000)
14 - 17 reserved -
18
0 to 20 mA
0 to 62000 (-31000 to 31000)
19 4 to 20 mA 0 to 62000 (-31000 to 31000)
20 - 21
reserved
-

DigiRail-2A
NOVUS AUTOMATION 5/5
REGISTERS 26 AND 27 – MEASURING UNITS OF THE CHANNELS
Will define the measuring unit for the channel when the input type is configured as thermocouple or Pt100.
Bit at 0 - °C
Bit at 1 - °F
REGISTERS 31 AND 32 – OFFSET OF THE CHANNELS
Allows performing small adjustments at the indication of the channel values. This parameter must be treated as a whole
number with sign.
REGISTERS 36 AND 37 – SQUARE ROOT FITNESS OF THE CHANNELS
Enables/disables the indication of the square root of the channel values. Only valid when the input type is configured as
being linear (mV, V or mA).
Bit at 0 - Does not extract square root
Bit at 1 – Extracts square root
REGISTERS 41 TO 44 – INDICATION LIMITS OF THE LINEAR CHANNELS
Will define the lower and upper indication limits of the channels when the input type is configured as being linear (mV, V,
mA). This parameter must be treated as a whole number with sign.
REGISTERS 51 TO 54 – INDICATION LIMITS OF THE CHANNELS
Will inform the lower and upper indication limits of the channels. This parameter must be treated as a whole number with
sign.
REGISTER 61 – DIAGNOSTIC STATE TIMER
Data in tenths of seconds, used internally by the DigiConfig software.
REGISTER 62 – DIGIRAIL MODEL
Provides the code of the DigiRail model. Internally used by the DigiConfig software.
Model
Amount
2A
1
2R
3
4C 4
REGISTERS 126 TO 150 – TAGS
DigiRail features some identification Tags, where characters can be written in order to help identifying the device, its
input channels and the units used when the input type is configured as being linear (mV, V or mA):
- Identification tag of the device (10 characters).
- Identification tag of the input channel (10 characters for each input channel).
- Identification tag of the engineering unit when the input type is configured as being linear (10 characters for each input
channel).