Level transmitter out of range
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I’m a newcomer; while using the hert375 transceiver to adjust the level transmitter, I encountered the following problems. I hope someone with more experience can help me solve them: 1. The transceiver cannot communicate with the level transmitter, or communication is possible only for a few dozen seconds before it stops again. The connections were checked and found to be fine. After adding a 250-ohm resistor, communication became completely impossible, even though the control system was set to manual mode. 2. The range of the level transmitter is 0-30 kPa, but since this did not match the actual liquid level, a calibration adjustment was made, changing it to -0.3-12 kPa; after that, it matched the actual liquid level in terms of percentage. No problems occurred during operation for some time, but recently the system stopped functioning and indicated an out-of-range condition. When communicating via a handheld device, the PV value read was 2.8 kPa, which is still within the calibrated range of -0.3-12 kPa. So why is it showing an out-of-range condition?
Is no one answering? Please give the answer again
There is interference; communication is often interrupted when such interference is present. In particular, check whether there is a 60Hz power supply in the vicinity, as this corresponds to an interference carrier frequency of 3KH
Interference is extremely problematic; proper shielding against interference must be ensured during the initial installation.
I think there might be a problem with your transmitter; either that or the supply voltage might not be correct, which could also cause this issue
The manual recorder cannot communicate with the level transmitter: one reason is the interference mentioned above, and another possibility is that the communication distance is too great.
Does your level transmitter display KPa? I don’t understand
I. If there is no communication between the manual recorder and the level transmitter, check two things: A: Verify that the voltage is correct; if not, check the control room and the wiring. B: Ensure that the total resistance of the circuit is between 250 ohms and 1000 ohms. II: The display screen of the level transmitter may be damaged, which is why no display is shown. III. A lack of communication usually indicates that the instrumentation equipment is damaged.
Regarding issue 1, in addition to the possible interference mentioned above, check whether the communication cable of HART 375 is in good condition; trying a new one might help. For issue 2, the system fails to display data and reports an out-of-range error, even though there is no actual out-of-range condition. Therefore, it is recommended to try replacing the DCs channel; I have encountered similar problems in my work
1. Problem of no communication: Incorrect wiring between the operator and the transmitter + resistor； Interference ； The transmitter is broken ； The system channel causes power supply issues. 2. The transmitter handheld device can be read, but no signal current is output; this is measured using an ammeter ； System channel failure; try another channel
My 375 communicator also cannot communicate with HART-enabled meters; using a 275 communicator works instead. It’s possible that the issue is related to the software version as well. Based on my assessment, there seems to be a problem with the circuit board inside the level transmitter
There is a communication issue with the handheld controller; it’s essential to ensure good contact
An out-of-range reading may be due to an issue with the range setting; check whether it is being used to measure vacuum.