Mass flow meter issue, waiting online
Thread Content
A mass flow meter, from Emerson’s 1700 series. The on-site meter display is normal, and the output current signal is also normal. However, after the signal is connected to the PLC (Mitsubishi PLC analog card), the pump operates normally during the first 20 seconds, but thereafter no display is shown on the screen, although the current signal remains normal. Need help. Waiting online; it’s really frustrating
When you say the output current signal is normal, do you mean the value measured when the output current signal circuit is disconnected, or the value measured by a milliampere clamp meter?
What is the voltage measured on the PLC side when the output current signal circuit is disconnected?
0V confirms that the PLC is passive
So, what is the voltage on the mass flow meter side when the output current signal circuit is disconnected?
So, what is the voltage on the mass flow meter side when the output current signal circuit is disconnected?
So, what is the voltage on the mass flow meter side when the output current signal circuit is disconnected?
All signals that can be monitored on-site at 24V and via the PLC have been checked; everything is normal
Oh, that only indicates whether there is a problem with that channel in the PLC. Disconnect that channel from the PLC completely and supply it with a passive signal of 4–20 mA to see if anything appears on the display
The PLC channel was also changed, but it didn’t work; when another flow meter was connected to that channel, everything worked fine! My head is killing me; I’ve been working on it for 2 days