You might want to use an external ADC such as the I-7017.
This ADC can be connected to the analog output of the load cell signal conditioner. The I-7017 can deal with 0..10 volt signals and it connects to the TriLog PLC via rs485.
The analog inputs to the I-7017 are differential the TriLog ADC inputs are single ended. Differential inputs help to overcome a lot problems with signal grounding between the 2 PLCs.
The input impedance of the I-7017 is grater than 20M ohm to both the signal and the ground (reference) inputs.
Best regards,
Gary d