FX3U-4DA – Analog Card Range not corresponding

So how does the FX3U-4DA accommodate Analog Output Signals? The following applies;

So how does the FX3U-4DA accommodate Analog Output Signals? The following applies;

1. The FX3u-4DA is indeed an analogue output card – which can provide a range of 4-20mA in the extremes – from minimum to maximum (or vice-versa)
2. if the perveived mA as a measured output value is well within the 4-20mA analog output range – then the mA value is highly possible and acceptable. (e.g. 17.5mA).
3. If however, the PLC is outputting a full range – which is supposed to equate a signal value of 20mA, and you are getting less (e.g.17mA) – then this is incorrect. There are reasons for this and the following are points to check;
   • Check if the actuator is calibrated 100% correctly to accommodate this signal rang of 4-20mA. Why is this important? Because, if the indicated 17mA is what is attained from a feedback signal (Such as a positioner or an I2P, then the problem is a matter of calibration.
   • IF the above mentioned problem is not applicable, then it could be a case of a damaged output card. It is must be pointed that ALL output cards for FA (And instrumentation) equipment is to be fuse protected (preferably by fast-blow fuses).
     • This includes both digital discrete outputs and analogue continues outputs.
     • This is to protect the hardware against short-circuits.
   • Without fuses – if a short-circuit occurs – even for a fraction of a second, the hardware is likely to be damaged.
     • If this is case – and any two output wires of your 4DA card touched momentarily – this could be the root-cause
   • To test this – replace the analog card and measure the signal again.
   • More information on the installation requirements can be attained HERE
4. It MUST be confirmed that the output of the PLC from the PLC program point of view, is indeed maximum (20mA) – of which the resolution is 32000

So how does the FX3U-4DA accommodate Analog Output Signals? The following applies;