IGD TOCSIN 750 Series - Interfacing to Remote Modbus Port; Modbus Command Structure

14
B A 0V DC
Screen B A 0V DC
RS485 Modbus
Comms Port
RS485 Modbus
Comms Port
Interfacing to the Remote Modbus Port
Tocsin 650/750 Controller (slave)
Master DCS/BMS
Note only the A,B and 0V DC Connections are
Used. 0V DC between master and slave should
be connected for correct operation and to prevent
damage to both master and slave systems
The Tocsin 640 controller has an in-built memory map allowing access to alarm status, panel status,
readings etc using Modbus RTU protocol. Wiring between units is as follows:
MODBUS INTERNAL MEMORY MAP ADDRESSES
COMMAND STRUCTURE
Parameter
Setting
1: Modbus Mode
RTU Mode Only
2: Operating Mode
Slave Mode Only
#1
3: Response Time
Maximum = 100mS
(5s for Zero Command)
4: Requests
Maximum = 32 per Second
5: Panel Address
100 to 131 (100=default)
6: Baud Rate
4800, 9600, 19200 (19200=default)
7: Start Bits
1
8: Data bits
8
9: Parity
None, Odd, Even
(Odd=default. None=T700 only)
10: Stop
1, 2 (1=default & T700 only)
11: Flow Control
None
12: Physical Interface
2 Wire RS232, 2 Wire RS485
(2 Wire RS485=Optional on T900)
13: Bit Order
Least significant bit transmitted first
14: Byte Order
Least significant byte transmitted first
15: Inter-byte spacing
Maximum = 1.5 bytes times
(781uS @ 19200 Baud)
16: Inter-packet spacing
Minimum = 3.5 bytes times
(1823uS @ 19200 Baud)