ICS for PDF Timeout setting

How can I change the Timeout settings for ICS? (SS4 08.11.11.584)

I am getting an error on some large files - 'TIMEOUT, ipmstnsrvm failed to complete within 1800 seconds'.- and need to increase the timeout value.

The setting has been modified in the IPLOT.cfg file - 'IPLOT_MSTN_TIMEOUT = 2400' - but this has not had any effect.

Thanks