KF2 to DIGI Etherlite 2 problems

Digi One IA/IAP
1

I have a 1770 KF2 module connected to a DIGI Etherlite 2 EIA422. I am using Realport drivers and have the KF2 set as follows:

Baud Rate 9600
Parity None
Duplex Full
Error Ck BCC
Data bits 8
Stop bits 1
Enabled Response no
accept dup msg yes
handshake off

Everything works fine except when traffic gets heavy on DH+ I get lots of timeout errors and slow response. We have checked the DH+ cabling and termination. On the TCP side, Realport never reports any problems and response time from other apps over Ethernet seems fine.

The cable from KF2 to DIGI does not have resistors or pin jumpers on the DB25 side, but this same cable has worked in the past.

Any Ideas?

2

Does the ping time between the Server running Realport and your Etherlite increase corresponding to the same time period the DH+ load gets heavier and you get slow responses?

3

No the ping time seems to remain quite constant, no matter what is happening to DH+

4

Can the DH+ use flow control?

I wonder if the errors aren’t due to lost data due to the buffer being overrun due to lack of flow control, and the slowness a result of the trashed packet needing to be resent.

This is what I think of when you say no flow control is being used but DH+ traffic gets heavy, and also explains the behavior you’re seeing as well as why Realport doesn’t report an error (it doesn’t care whether you use flow control or not, it only does what you’re telling it to be that right or wrong).