Issue
How can Sigma IC Hardware Alarms be disabled?
Environment
Sigma
IC
Integration Controllers
Hardware Alarms
Cause
Large numbers of alarms were caused after a power fail.
Resolution
Hardware alarms are generally a good thing as they advise of a problem on the system, but should it be necessary to disable them, then this is achieved by modifying the Gateway.txt file.
There are a range of Sigma IC's available and there are differences between them, so to ensure the correct changes are made, the appropriate IC documentation should be reviewed.
In this example the Gateway.txt of an IC-Modbus will be examined.
Each object entry in the Gateway.txt can consist of up to nine fields as follows - 55,1,3,101,1,2,0,0,0, and it is the ninth field that controls the Hardware Alarm Suppression.
If the ninth field is not used or is set to zero, then the hardware alarms will operate as normal, but if the ninth field is set to 1, then these alarms are disabled.
Below shows a section of the Modbus Gateway.txt, where the object field entries are defined.
; Format of list, 8 or optionally 9 parameters per entry:-
; 1 Sigma Object Number,
; 2 Controller Address - Hiromatic Unit not units on sublan
; 3 Modbus Command ( 3, 4, 16, 144)
; Crompton meters IC uses functions listed (serial only, not TCP)
; 3 Read Holding register (AI)
; 4 Read Input registers (AI)
; 16 Preset multiple registers (AO)
; 144 Set MSB - Write Demand time (DO)
; Note :- Resetting the Demand Period for the CROMPTON is a special case.
; The most significant bit must be set, i.e. Function = 144, and a DO Object
; must be used. This ensures that the Demand Period is only reset
; when the DO Object switches from 'OFF' to 'ON'
; 4 Register Address
; Use the formula
; Register Address = Address-1. E.G. for return temp, at address 233
; enter the value 232.
; 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)
; Maximum 7 objects
; Special case: 32- bit data Input objects may be read in a single
; transaction
; Note: This is applicable to Function Codes 0x03 and 0x04 only.
; Format: 0xST02
; where-
; S = Swapped? (0 - unswapped; 1 - swapped)
; T = data type (0 - 16 bit; 1 - unsigned 32 bit; 2 - signed 32 bit;
; 3 - float 32 bit)
;
; 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
