Why isn’t it displayed on the DCS?
Thread Content
The expander speed feedback signal is transmitted from the field via a cable as a 4–20mA signal, which is then fed into the AI card channel; however, it was found that the speed signal displayed on the operator station interface appeared intermittently. Check the cable; the mA signal has indeed been transmitted to the card side. The mA signal for the AI channel was applied using a manual controller, and the operation station interface displayed normally. After changing the AI channel and reconnecting the cable, why doesn’t the control station still display the speed value? I’m asking the experts here – what’s going on? Is there a problem with the cable shielding?
It’s possible that the instrument cable is being interfered with by the high-voltage cable; we’ve encountered this issue before, where the instrument cable ran through the high-voltage cable conduit, and fixing that resolved the problem.
Generally, this is due to interference, design issues, or problems on the part of the construction team, which cause the instrument signal wires to be too close to the power wires; moreover, high-voltage power wires need to be kept even further away.
Generally, this is due to interference, design issues, or problems on the part of the construction team, which cause the instrument signal wires to be too close to the power wires; moreover, high-voltage power wires need to be kept even further away.
Is it a problem with the card, or was there an error in the power distribution settings?
Is the double ground caused by the signal wire of the speed detection sensor touching the casing?