Operating Instructions

Commissioning
Configuring communication
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72 | 118
Siemens A5E36496664A_f
Smart Infrastructure 2021-10-11
Modbus RTU protocol
Parameter Description
p0015 Select value 109 "Modbus RTU" during basic commissioning.
p2021 Valid Modbus RTU addresses: 1…247
Invalid Modbus RTU address: 0
p2020 Fieldbus baud rate
● Baud rates from 4800 bps to 187500 bps can be set for communication.
● Factory setting: 19200 bps
p2024 Modbus timing
● Index 0: Maximum slave telegram processing time
Maximum response time from the slave to the master.
● Index 1: Character delay time
Maximum permissible delay time between the individual characters in the
Modbus frame (Modbus standard processing time for 1.5 bytes).
● Index2: Inter-telegram delay
Maximum permissible delay time between Modbus telegrams (Modbus
standard processing time for 3.5 bytes).
p2029 Fieldbus error statistics
● Displays receive errors on the fieldbus interface.
p2031 Modbus parity
p2040 Process data monitoring time [ms]
● Setting the time to monitor the process data received. If no process data is
received within this time, an appropriate message is output
● Factory setting: 10000 ms
● The setting 0 ms deactivates the monitoring function.
BACnet MS/TP
Parameter Description
p0015 Select value 110 "BACnet MSTP" during basic commissioning.
p2021 Valid BACnet addresses: 1…127
p2020 Fieldbus baud rate
● 6: 9600 bps (factory setting)
● 7: 19200 bps
● 8: 38400 bps
● 10: 76800 bps
p2024 Processing times
● [0]: 0ms … 10000 ms, maximum processing time (APDU timeout)
Factory setting: 1000 ms
● [1…2]: No significance for BACnet