Why is the modem "MDLS144 onbit" no longer working on a new PCD?

FAQ #101718

If the "MDLS144/288 Data9600 onbit" modem is connected to a "non Saia PCD® COSinus" system (PCD1.M1, PCD2.M1) then it's possible to establish a modem connection to those systems but if the same modem is connected to a "Saia PCD® COSinus" System (PCD1.M2, PCD3, PCD2.M5) then it isn't possible to establish a connection.


The reason of this behavior is the difference how the FW of the PCD does handle the modem.

In general the FW does send the as first step the "modem reset sting" and after this the FW does check the status of the DSR / CTS signal before in a second step the "modem initialization string" is send to the FW. 

  • On the "non Saia PCD® COSinus" systems the DSR or the CTS signal have to be high before to go to the second step.
  • On the "Saia PCD® COSinus" systems the DSR and the CTS signal have to be high before to go to the second step.

To use the "MDLS144/288 Data9600 onbit" modem on "Saia PCD® COSinus" systems its necessary to set the DSR to high during the first step of the modem initialization.
To do this it's necessary to adapt the "modem reset sting" on the device configurator/HW-settings on Saia PG5® .

The "modem reset string" has to be changed from:

The "modem initialization string" remains the same.
The modification could be used on "Saia PCD® COSinus" system as also on "non Saia PCD® COSinus" systems.



PCD3 / Mxxx

PG5 2.0 / Modem

PCD1 / M2xx0

PCD2 / M5xxx

PCD2 / M1xx

Last update: 28.05.2015 13:06

First release: 27.01.2012 15:02

Views: 19671

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.