Siemens Milltronics BW500, Operating Instructions Manual

Page: 147 / 220

Communications
11.5 Modbus RTU/ASCII Protocol
BW500 and BW500/L
Operating Instructions, 12/2016, A5E33482052-AD
145
For the I/O, the assigned registers represent the logic status (e.g. open or closed) of the I/O as
configured. Discrete inputs are configured via P270, auxiliary input function; while relay outputs
are configured via P100, relay function.
The I/O are mapped into the respective input and output registers, R41,070 and R41,080, as
follows:
R41,070 R41,080
Input Bit Output Bit
1 1 1 1
2 2 2 2
3 3 3 3
4 4 4 4
5 5 5 5
For the mA I/O, the assigned registers represent the mA level (e.g. 0 to 20 mA) of the I/O as
registered in P911 and P914, mA output test (output value) and mA input value.
The mA I/O are mapped into the respective input and output registers:
Input Register Output Register
1 R41,090 1 R41,110
2 R41,091 2 R41,111
3 R41,112
For 0 to 20 mA I/O, the register value ranges from 0 to 20,000. For 4 to 20 mA I/O, the register
value ranges from 4,000 to 20,000. If the 4 or 20 mA values have been trimmed, then the
register value is adjusted accordingly; e.g. an I/O value of 22 mA would be registered as 22,000.
Diagnostic (R41,200)
Refer to Troubleshooting (Page 193)
PID Tuning (R41,400 – 41,419)
1)
For BW500 set up for PID control, several registers have been provided for tuning. Refer to PID
Control (Page 107) and the associated parameters as listed in the register map.
Note
Before you can change any of the setpoints, P799 must be set for remote control.
1)
Not available with BW500/L.