Why can the PCD7.LRxx-P5 IRM room controller as S-Bus master, not read/write datas (inputs and outputs) from S-Bus slave devices via S-Bus?

FAQ #102029

The PCD7.LRxx-P5 IRM room controller can be operated on the RS485 interface as an S-Bus master. 

The PCD7.LRxx-P5 IRM room controller supports all S-Bus telegrams except the 2 telegrams:


  • Read Input
  • Write Output

This means that it is not possible with the PCD7.LRxx-P5 IRM room controller, to read from the S-Bus Slave devices directly via S-Bus inputs and to write the outputs of the S-Bus Slave devices.

If S-Bus Slave devices are used which use the S-Bus telegrams 'Read Input' and 'Write Output', then replace these devices with E-Line RIOs.


If the PCD7.LRxx-P5 act as S-Bus master, then it’s not possible to access S-Bus slaves devices with the S-Bus telegrams ‘Read Input’ and ‘Write outputs’, because this telegrams are not implemented in the firmware for the PCD7.LRxx-P5.


Concerned products:

PCD7.L1/2/3/x modules or 3rd party S-Bus slave devices which do need the ‘Read Input’ and ‘Write outputs’ S-Bus telegrams to exchange data’s between the master and the slave



Replace the PCD7.L1/2/3/x modules or 3rd party S-Bus slave devices with E-Line RIO’s



PCD7 / Rxx-P5

Last update: 29.01.2019 09:04

First release: 29.01.2019 09:04

Views: 4

The requested software / document is no longer marketed by Saia-Burgess Controls AG and without technical support. It is an older software version which can be operated only on certain now no longer commercially available products.