Sigma IC3-Modbus - IP Modbus devices fail to respond to the IC-Modbus.

Issue

Communications with IP devices does not work.

Product Line

Satchwell Sigma

Environment

IC3-Modbus

Modbus

IP devices

Cause

The IC3-Modbus is configured to poll two IP Modbus servers, but only the first configured server communicates.

Resolution

The IC3-Modbus uses a Gateway.txt file to list the Modbus IP servers, and the registers required. This file consists of general setup information and a section where the servers and registers are listed. 

Note that the Sigma objects but be sequential in the list.

Final section of the Gateway.txt file.

; 7  Min Value (output objects only, 0 for inputs)
; 8  Max Value (output objects only, 0 for inputs)
; 9  Hardware Alarm Message Suppression Flag (optional),
;   0 = Don't suppress,   1 = Suppress

; read a single 16 bit register
;51,1,4,062,1,1,0,0,0
; read three 16 bit consecutive registers to objects 52, 53, 54
;52,2,4,065,1,3,0,0,0
; read two 16 bit consecutive registers to objects 55, 56
;55,1,3,101,1,2,0,0,0

; read two 16 bit consecutive registers containing un-swapped 32 bit unsigned data
;68,2,3,110,1,0x0102,0,0,0
; read two 16 bit consecutive registers containing swapped 32 bit unsigned data
;70,2,3,112,1,0x1102,0,0,0
; read two 16 bit consecutive registers containing un-swapped 32 bit signed data
;72,2,3,114,1,0x0202,0,0,0
; read two 16 bit consecutive registers containing swapped 32 bit signed data
;74,2,3,116,1,0x1202,0,0,0
; read two 16 bit consecutive registers containing un-swapped 32 bit float data
;76,2,3,118,1,0x0302,0,0,0
; read two 16 bit consecutive registers containing swapped 32 bit float data
;78,2,3,120,1,0x1302,0,0,0

The section below lists the input objects, which consist of a number of fields, the fields are made up as follows;

1   Sigma Object Number,
2   Controller Address
3   Modbus Command ( 3, 4, 16, 144)
4  Register Address
5  Min time in seconds before polling same controller (Default 1 second)
6  Number of consecutive objects to read (inputs objects only, 0 for outputs)
7  Min Value (output objects only, 0 for inputs)
8  Max Value (output objects only, 0 for inputs)
9  Hardware Alarm Message Suppression Flag (optional),

Notice that the Sigma object numbers are in sequence, they must be sequential.

52,1,3,0x804,1,0x1102,0,0,0
54,1,3,0x808,1,0x1102,0,0,0
56,1,3,0x80C,1,0x1102,0,0,0
58,2,3,0x810,1,0x1102,0,0,0
60,2,3,0x814,1,0x1102,0,0,0
62,2,3,0x818,1,0x1102,0,0,0
64,2,3,0x81C,1,0x1102,0,0,0

OUTPUT

111,1,144,0,1,1,0,100,0
112,2,144,0,1,1,0,100,0
113,1,16,4,1,1,1,30,0


; Controller to IP address mapping table (Serial comms will ignore this table)
;   1 - Controller Address
;   2 - IP address of the Controller or the gateway/router to access the
;       controller
IP_ADDRESS_TABLE

Configure the Controller IP addresses.

1,10.158.100.114
2,10.158.100.205

; End of Gateway.txt file. Do not write below this line.