Ah... I seem to remember there are differences between FX1/2 analogues & the newer FX3, originally when the FX3 came out (completely compatible with FX1/2, there were no FX3 extension modules so it used the FX2 type, If yours is the older module then it would have 0-2000 for AO & 0-4000 for AI, there were also differences on the AD modules the FX2N type the analogue values were in buffer memories 10-13 (I think) whereas on the FX3 this moved to 11-14 or something like that, a colleague of mine rang me up he was having problems with an analogue input module, It turned out after reading the differences between the FX2 & 3 modules the buffer memories had changed, it sounds like the other system is using the FX3 & the module you have is actually an FX2 module, even if it states it is an FX3U-4DA it could actually be an FX2, It is possible that the early hardware was based on the FX2 firmware or that it is a clone, seen clones (and there are many) that are sold as FX3 but are actually based on the FX2.