September 2001
GFK-1859B
I
MPORTANT
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RODUCT
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NFORMATION
READ THIS INFORMATION FIRST
Product:
VersaMax
Ethernet Network Interface Unit
IC200EBI001-AC with Firmware Release 1.20
Introduction
This document contains important information not available in any other publication; therefore, we strongly
advise you first read and then save this document. This document discusses firmware release 1.20, which
corrects the problems described in the sections “Problems Resolved in this Firmware Release (1.20)” and
“Important Operational Notes” below.
Important Operational Notes for Firmware Release 1.20
Number of Allowed Connections for Modbus Protocol Mode Reduced from 10 to 1
For the Modbus Protocol mode, the number of allowed connections has been reduced from ten to one. This is
required to facilitate the message timeout function, described below.
Addition of Message Loss Timeout Function for Loss of Communications Problems
In previous releases, if the Ethernet connection was broken or the application failed to communicate, outputs
held their last state values for a fixed time of 10 to 11 seconds, then reverted to their configured default state
values. For applications where this behavior is not acceptable, a new “message loss timeout” function has
been added to the ENIU.
Configuration of this function was facilitated by extending the use of the existing Update Timeout parameter,
found on the Consumed Exchange tab of the ENIU hardware configuration window. Starting with Release
1.2, the Update Timeout parameter has dual functionality. In EGD mode, its function has not changed. In
Modbus mode, it is now used to set a message loss timeout period. If the ENIU does not receive a valid read or
write message within that timeout period, the ENIU commands its controlled outputs to go to their configured
default state values.
During normal operation, each new read or write message resets the timer. So the Update Timeout parameter
must be set to a value 2 to 2.5 times greater than the message rate to ensure that a timeout does not occur
under normal operation. In the case where a timeout occurs due to a loss of communications, the ENIU waits
for a new Modbus connection to open and for receipt of a write message before bringing outputs out of their
default state.
Note that the Update Timeout parameter will be automatically set to 2 seconds if Autoconfiguration is used or
if a new default configuration is stored from the configuration software. Also note that if the Update Timeout
parameter is set to 0 (zero), the message loss timeout function is disabled, and the ENIU will hold its last state
for 10-11 seconds as in previous releases of the module. The range of time values allowed for the Update
Timeout parameter is 10 to 3,600,000 milliseconds. This timer operates at the Application layer.