Coverting a GEM 80

Hi we are looking at upgrading our MicroGem 303 series PLC to a Siemens S7. Does anyone know of a fast IO bridge that will allow us to access the GEM I/O from the seimens PLC so we can run it in shadow mode without having to parallel up the I/O.
The current GEM 80 PLC's uses starnet HDLC to communicate. We are investigating the use of a Comsoft SDLN device to convert the HDLC message to a TCPIP message. If anyone has had any experience with this unit some feedback would be good.
Thanks

Hi Steve,

Any succes wiht your proposed method. I am currently using Comsoft SNL2-E (HDLC to TCP/IP converter) to act as a gateway to establish the communication between GEM80 Startnet with Siemens Step 7 TCP/IP. SNL2-E communication with S7 over TCP/IP has no issue. However I have problem to establish the communication between the Gateway (SNL2-E) and GEM80 Startnet over the serial port on the Gateway which is using RS422 (HDLC-UNC protocal). Can you share your experrience of establishing the commuication of Comsoft gateway and GEM80?

Hi Augustine
We never went down the path of using the Comsoft product, we decided to install HPCi controllers manufactured by Converteam. This is the old GE Alstrom and the upgrade path offered for the GEM. It supports Starnet, Profibus and Ethernet. We are yet to install this product but currently have a contract with Converteam to install them in August.
Good luck & hope all works out
Steve