Applies To:
  • CitectSCADA 4.xx, 5.xx, 6.00
  • CitectHMI 4.xx, 5.xx, 6.00

When WAGO I/O modules are used with the MODNET driver, successive reconnects after a network failure appears to result in some resource in the module being consumed so that reconnections are not possible after a small number of reconnects, until the module is power cycled. This article outlines some configuration in the ports database entry which will eliminate this. 

For WAGOs and (optionally) other TCP/IP devices, another parameter must be introduced in the ports form:


where n is a tcp port number.

A range of TCP port numbers which is identified as free is 47809 - 47999

The configuration of the special options field of a WAGO port would then be something like:

-i10.170.6.207 -LP47809

The next one would be

-i10.170.6.208 -LP47810


The -LP numbers may be reused on the other I/O server.

(the -i and -LP are not case sensitive, but these representations leave no doubt as to which are the letters i and L)

These modifications drastically improve the ability for Citect to reconnect to WAGOs after network connection failure and restore to the PC.


WAGO TCPIP IO Listen Port