Here is a quick script to get the svn numbers of the TwinCAT PLCs:

#!/bin/csh
ezcaread ${1}:SYS-ETHERCAT_C1PLC1_SVNREVISION
ezcaread ${1}:SYS-ETHERCAT_C1PLC2_SVNREVISION
ezcaread ${1}:SYS-ETHERCAT_C1PLC3_SVNREVISION
ezcaread ${1}:SYS-ETHERCAT_X1PLC1_SVNREVISION
ezcaread ${1}:SYS-ETHERCAT_X1PLC2_SVNREVISION
ezcaread ${1}:SYS-ETHERCAT_X1PLC3_SVNREVISION
ezcaread ${1}:SYS-ETHERCAT_Y1PLC1_SVNREVISION
ezcaread ${1}:SYS-ETHERCAT_Y1PLC2_SVNREVISION
ezcaread ${1}:SYS-ETHERCAT_Y1PLC3_SVNREVISION

and here are the results:

H1:SYS-ETHERCAT_C1PLC1_SVNREVISION = 2406
H1:SYS-ETHERCAT_C1PLC2_SVNREVISION = 2402
H1:SYS-ETHERCAT_C1PLC3_SVNREVISION = 2402
H1:SYS-ETHERCAT_X1PLC1_SVNREVISION = 2357
H1:SYS-ETHERCAT_X1PLC2_SVNREVISION = 2357
H1:SYS-ETHERCAT_X1PLC3_SVNREVISION = 2357
H1:SYS-ETHERCAT_Y1PLC1_SVNREVISION = 2357
H1:SYS-ETHERCAT_Y1PLC2_SVNREVISION = 2325
H1:SYS-ETHERCAT_Y1PLC3_SVNREVISION = 2325

These are the most recent versions for the respective PLCs.