Currently my client has an AS/400 which talks to a B1 board over a serial link. In preparation for upgrading their system and using Ethernet for communication we installed an E1 board and connected the serial interface to the AS/400 just like the B1. In theory the AS/400 should communicate with the E1 just like it did with the B1 using the Optomux protocol. In practice things didn’t work so well.
I used a data scope to monitor communications both with the old B1 in place and then with the new E1 in place. The B1 traffic looks exactly like I expect as per the Optomux protocol documentation. The E1 however seems to send an extra reply message after the first command sent by the AS/400. This extra reply is throwing the AS/400 program off and things go downhill from there.
Portions of those communication logs with markups/comments are here:
(Sorry, I tried to attach these files to this forum post but was not successful.)
Updating the programming on the AS/400 is not an easy option. I’m hoping someone might be able to explain why the E1 is sending me the extra reply message and if there is a way I can make it behave more like the B1. Note that I have not connected the Ethernet interface at all yet. Once that interface is established can the E1’s behavior be configured in some manner with the Opto software?