Siemens HMI Adapter was designed to work with an older version of Siemens PC Adapter. The HMI driver was designed to work with part number 6ES7-972-0CA11-0XA0 (SCPLN307900). However, Siemens has released new PC adapters with higher baud rates that are not currently supported. This includes the 0CA20 and the 0CA21.
Please note that the Siemens PC adapter is not the same as the MPI cable. It is a separate adapter the user has to buy from Siemens.
The adapter is able to communicate at the higher speed of the 6ES7-972-0CA11-0XA0 adapter. However, it falls back to its default baud rate of 9600 whenever serial communication is disrupted. Although this behavior can be observed by the fast blinking power LED, there is no way to reconfingure the driver for this oc
urrence. Lookout maintains the settings which were originally configured, which would make it impossible to re-establish communications without operator interaction. Hence, the communication speed is restricted to 9600 baud. Also, the communication settings are not configurable. The device will ONLY work with the following settings:
Start bits: 1
Data bits: 8
Parity: ODD
Stop bits: 1
Siemens PC Adapters