Recent content by David_2

Answer: yes. Whatever you power the loop powered transmitter with, is 'loop power'. It might be a stand-alone DC power supply. It might be a DC power supply that is part of the analog input module. The transmitter is the load and it regulates the current in the loop, so the DC power...

When a single device works OK but additional signal inputs cause offsets or faults up-scale or down-scale when devices are added to a non-isolated analog input board, a known cause is common mode voltage ground loops. HART transmitters are typically isolated (the housing is grounded, but the...

I have no background in fire alarms. In process systems, the annunciated output of a latched alarm (a horn, for example) can usually be silenced by acknowledging the alarm, which disables the driver circuit to the annunciator. However, if the alarm state remains 'active' over some period time...

Thanks for the links to the manuals. The Operating Instructions manual states that the HART write protection can be switched on and off using the HART WRITE PROTECT device function (→ "Description of Device Functions" manual), (Bottom of page 64). But the word "write" does not appear in the...

Is there an interposing relay whose contacts are stuck closed?

You'll have to sketch out exactly what connects to what with links to the hardware manuals and post it here.

If you use HART, then HART needs 250 Ohms of loop resistance to function properly. In either case, the 4-20mA circuit needs to be powered. Either from an external (24V) DC loop power supply or from the DC power supply that drives the thermal dispersion measurement. If the SCADA expects an...

Does SCADA supply loop power? Or does SCADA want and expect a powered 4-20mA signal? How did you wire the Sierra 4-20mA output? The top diagram is for a passive, loop-powered 4-20mA (where SCADA might provide the DC power to power the loop). The bottom diagram is where the DC power...

1. The bottom photo lacks a wet leg for isolating the transmitter from direct steam impingement. The transmitter needs to be protected from direct steam which will cook and destroy the electronics. A wet leg is used to isolate the transmitter from the steam by a column of water. The column of...

what am I missing? The negative sign on the LRV; you are subtracting a larger number from a smaller number, with a negative result. For those who haven't a clue what this is about, this is an "interface" application where the desired level is the interface level between oil (SG 0.86) and water...

It works for me ! ! ! 5 stars * * * * * I normally only use the data display, but I really like the traffic display with easy-to-read separate lines for Tx and Rx. Modscan's Master app just jams all the traffic in successive lines/rows and it's hard to read. The flowmeter crowd that has...

1. The configured zero is not zero, but is -6 in w.c. 2. Mud crap/sludge from the tank got into the impulse tubes. Mud/sludge has a higher SG than water, so a smaller 'level' of mud/sludge will produce more 'pressure' than 6 inches of water. examples: high side 0" minus low side +27 inches...

I'd love to download it but too many options. My pc runs Windows 11, Version 25H2, Windows 11, Version 25H2 10.0.26200 x64-based So which download do I choose? Qt5 or Qt6 or the x86?

Wow, what a find. I had no idea there was a repository like this. Maybe I should upload the hundreds I've looked through over the years for helping out on this forum. Thanks for letting us know.