SmartAlarm Instruction Manual Rev 2
Page 107 of 115
Write Multiple Coils
– Function 15 - Read Request – Master
Coil Address
Indicates first coil address to be written. Typically the first channel contact
status on an alarm card
“channel 1” would be coil address 00 01.
To write the contact status coils use address range 1- 8.
Note: To initiate input status change via message 15
“Input via serial comms”
must be selected for each channel. Selection is via the configuration software.
Quantity
This represents the number of coils (Channels) the master wishes to write
Byte Count
This represents the number of data bytes sent
Data
This represents the status of the coil to be written
0 = Contact Normal
1 = Contact Abnormal
Write Multiple Coils
– Function 15 –
Read Response - Slave
Coil Address
Indicates first coil address to be written. Typically the first channel contact
status on an alarm card “channel 1” would be coil address 00 01.
Quantity
This represents the number of coils the master has written
Typical Example of Message Format
To write alternate contacts abnormal on a 24 way SmartAlarm where each
alarm card is treated as an individual node. The following message format
would have to be repeated 3 x times, once for each card node address.
RTU
ADDRESS
FUNCTION
REGISTER
ADDRESS
No Of
REGISTERS
BYTE
COUNT
DATA
ERROR
CHECK
01
0F
00 01
00 08
01
AA
43 2A
Example shows message for first card, Comms address offset 0.