EJA differential pressure transmitter, FF fieldbus, fault code AL22
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A small unit per set, using a fieldbus (Yokogawa). There is a pressure gauge that shows the IOP; upon on-site inspection, it is an EJA differential pressure transmitter used to measure the pressure in a nitrogen tank. The gauge indicates 0 kPa (in reality, this tank has not been used yet, so the pressure inside it is also 0 kPa), but the gauge still shows the AL 22 code; after searching for a long time, I was unable to find out what this code means. I’m not very familiar with fieldbuses, so I don’t know whether it’s due to the meter or the communication system. I’m hoping experts can give some advice. It’s quite urgent, as the process will be using this tank.
An IOP indication indicates an open-circuit alarm; check whether the power supply is functioning properly, whether the wiring polarity of the field instrument is reversed, and also examine the output current of the instrument itself.
Thank you, it’s fixed. AL22 indicates that the table is OUT OF Service. You can make the modifications using software.
Use the controller with FF on it, model 475, to communicate and diagnose the issue; the results will be displayed there. Follow the instructions given and everything will be fine
I forgot to mention that if you don’t have a 475 with a bus, you can ask me for help; I have some on hand