90
INM MTL SUM5 Rev 7
DRAFT - 09 June 2021 DRAFT - 09 June 2021
33 MODBUS SLAVE – STANDARD COMMUNICATIONS
Function Descriptions
This section describes the process of reading from and writing data to a SmartAlarm annunciator.
33.1 Read Coil Status – Function 01 – Read Request – Master
Coil Address
This is used to address the “start” channel to be read, typically the rst channel “channel 1”
contact status on alarm card would be coil address 00 01
To read the contact status coils use address range 1- 8
To read the alarm status coils use address range 11- 18
To read the disable status coils use address range 21- 28
Number of Coils
This represents the number of coils (Channels) the master wishes to read. The range is 1- 8.
33.2 Read Coil Status – Function 01 – Read Response - Slave
Byte Count
This represents the number of data bytes sent
Data
Data returned depends on coil address originally specied by the master.
Coil address 1 - 8 returns Contact status data
0 = Contact Normal
1 = Contact Abnormal
Coil address 11 - 18 returns Alarm status data
0 = Alarm Normal
1 = Alarm Abnormal
Coil address 21 - 28 returns Disable status data
0 = Channel Enabled
1 = Channel Disabled
To Next Page
Loading...
Need help?
General
