Honeywell Siemens Modbus Comm Problem

Hi all, i am trying to establish the communication between Honeywell epks scada system and Siemens s7 400 using modbus tcp ip. The digital is working fine, but analog was having errors. Honeywell system report receive of one byte extra than expected and due to error accumulation will fail after some time. During testing I change Honeywell controller to read from sec Siemens controller only and tht make the comm healthy. Do u face that before? And what can be the reason for primary controller fail?
This is a problem utilising the standard Honeywell Interface with the Siemens standard Interface. What you must do is first establish that the protocol is 100%. I have used an Emerson to Siemens interface where they had an automatic reset of the messages on the Siemens side, this was wrong! The Honeywell Interface is a little bit more unusual but works extremely well, what you have to do is select the right format for the numbers being transferred. This is select-able. Remember you will have a byte format of say 1234 for the source word, when the interface triggers it may be looking at 3412 or 4321 what you have to do is to adjust to the byte order which is correct. To do this is by the interface set-up, once you select the right format then the rest is easy. This is menu driven.