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

Connecting More than 10 I/O Devices on a Tinec or Sinec Network.

We have set up 12 I/O devices using the Tinec 32 bit driver to TI500 series PLCs and find that Citect will only communicate with up to 10 I/O devices max. We have tried the debug all in the Citect kernel window and found some strange requests/responses as per below;

Tue May 05 09:00:42 1998 141:08:29.733 WRITE: tf_get_path_ref : appl_path : 0 Length 0
Tue May 05 09:00:42 1998 141:08:29.733 ERROR: tf_state_path : OK connection up Length 0

The Siemens TF Diagnostics indicates that all PLCs are able to communicate. We have checked all addresses in the PLCs and if we take any two PLCs off line, Citect communicates with up to 10 PLCs OK.


Check the Siemens configuration file stf_conf.dat;

The parameter max_appl_rel=10, max. application relations is set to 10 by default. Increase this value to the number of I/O devices connected to your system.

You can adapt the Sinec TF Library to suit your needs. The configuration file needs to be in the same path as the executable user program (Citect) since it is read when the Sinec TF library is initialised.

Note: To facilitate correct debugging operation of the Tinec driver a new Tinec.dll is required for Citect Version 4.xx, 5.00 & 5.01. Use the current driver files on the Citect Website.