ACL CSC400 - Modbus Register Reference

41
Commonly Used CSC400 Modbus Registers
Notes:
- SCADAPack Register Addresses are listed for reference when programming SCADAPack PLC units.
- See the CSC400 Modbus Installation Manual for additional registers and specific details about reading and writing
registers.
Function Code 0x01 - Read Coils
Function used to read the state of each relay. Read Coil function code 0x01 can read all relay coils in two bytes.
Example PLC
Register
Address
Coil
#
Modbus Coil
Address
Description
Type
Notes
1 1 0 "AUX1 Relay" control
relay
Auxiliary
Control relay
Dry contacts,
max 0.12A @ 30VDC
1 = relay ON
2 2 1 "AUX2 Relay" control
relay
Auxiliary
Control relay
Dry contacts,
max 0.12A @ 30VDC
1 = relay ON
3
3
2
IGN1 Pilot solenoid relay
Solenoid relay
1 = relay ON
4
4
3
IGN1 Main solenoid relay
Solenoid relay
1 = relay ON
5
5
4
Alarm relay
Control relay
0 = relay OFF = Alarm
condition. 1 = relay ON,
no Alarm
6
6
5
Not used
N/A
Reserved
7
7
6
Proof of closure, IGN1
output relay
Control relay
1 = relay ON
8
8
7
IGN1 Temperature Main
solenoid relay
Solenoid relay
1 = relay ON
9
9
8
IGN2 Pilot solenoid relay
Solenoid relay
1 = relay ON
10
10
9
IGN2 Main solenoid relay
Solenoid relay
1 = relay ON
11
11
10
IGN2 Temperature Main
solenoid relay
Solenoid relay
1 = relay ON
12
12
11
Proof of closure, IGN2
output relay
Control relay
1 = relay ON
Function Code 0x02 - Read Discrete Inputs
This Function is used to read the state of each input. 1 = ON, 0 = OFF (unless otherwise stated)
Example
PLC
Register
Address
Input
#
Modbus
Discrete
Input
Address
Inputs
Byte
Input Bit
Description
Notes
10001 1 0 0 0 (LSB) Igniter 1 Alarm input 1 = Alarm signal high
(Alarm indicated)
10002
2
1
0
1
Igniter 1 Valve input
1 = Valve signal high
10003
3
2
0
2
IGN1 Main solenoid
1 = Main solenoid is on
10004
4
3
0
3
IGN1 Pilot solenoid
1 = Pilot solenoid is on
10005
5
4
0
4
IGN1 T/Main solenoid
1 = T/Main solenoid is on
10006
6
5
0
5
Reserved