I am working with Honeywell Smart Line Transmitter STD700 Series
The transmitters connected to the DE stem cards are pressure units that are having issues. They are all newer model SmartLine series.
STD720 (DE)
STD740 (DE)
The transmitters are not damaged by the near lighting strikes causing this issues. The DE signal affected causes the DE stem card not see the input from transmitter intermittently which causes trip. The DE signal is either too noisy for DE stem card to recognize or DE is driven high or low outside of tolerance of stem card. Customer thinks that if stem card had longer threshold or delay in recognizing valid DE input this might help with the problem. We are adding LP terminal blocks now to existing transmitters to see if this helps in any way but customer wants to go down this path as well. Again – the existing SmartLine pressure transmitters that are communicating analog and not DE to this same TDC are not having any issues.
The transmitters connected to the DE stem cards are pressure units that are having issues. They are all newer model SmartLine series.
STD720 (DE)
STD740 (DE)
The transmitters are not damaged by the near lighting strikes causing this issues. The DE signal affected causes the DE stem card not see the input from transmitter intermittently which causes trip. The DE signal is either too noisy for DE stem card to recognize or DE is driven high or low outside of tolerance of stem card. Customer thinks that if stem card had longer threshold or delay in recognizing valid DE input this might help with the problem. We are adding LP terminal blocks now to existing transmitters to see if this helps in any way but customer wants to go down this path as well. Again – the existing SmartLine pressure transmitters that are communicating analog and not DE to this same TDC are not having any issues.