Recent content by Carl_E

Steam pressure is greater than than the water supply pressure so the downstream low side DP port senses a higher pressure than the upstream water pressure at the DP's high side port; so DP goes negative. DP = High side minus low side.

Check out Panametrics (GE?) transit time clamp-on ultrasonic flow meter. I believe they have transducers rated for 500 Deg F. Last time I checked, clamp-on assumes a full pipe; I don't think even multi-path can deal partially full pipe.

Presumably you are using a Function code 03, read Holding Register(s), or 04, read Input Register(s) for reading the real (floating point) value. Which Function Code are you using to read the boolean value supported by the master/client and is that Function Code supported? What is the...

I'm sure the number of incorrect wiring combinations for 2 wire 485 is finite, but even one is more than I want to tackle on my time off. Why don't you tell us what you found and the implications? We'd all be interested to find out even if we're not willing to do labor through the details.

I'm not sure what the "destination call" consists of, but for automation it needs to be some form of electrical signal. Tie that electrical signal into the PLC and let PLC logic do its thing. If the HMIs need to be updated, then the PLC had the data to update the HMIs.

Google DLMS Modbus protocol converter gateway and you'll find a couple commercial products.

>Has anyone had this happen before? Yes. Your evaluation of the fault is correct.

I interpret "MODBUS Messaging on TCP/IP Implementation Guide V1.0b", section 3.1.2, as any message (source either client or server) where the message length field data does not correspond with the actual message length as an invalid messageto be discarded and an error response generated. It's...

>I'm not too familiar with MODBUS. That won't make any difference because the documented protocol is not Modbus. It bears some similarities, but a Modbus RTU master will never get a reply message from your slave inverter because the inverter protocol is not Modbus. Yes, Modbus and this...

What is the value of the flow measurement at that point? Apparently, not enough to exceed the cost of the energy loss.

Change to a higher range on both the transmitter and the DCS.

>replacement flame scanners >Aftermarket is acceptable. Due to the safety nature of flame scanners, good practice is same brand replacement. Flame scanners are expected to connect to a flame safety controller of the same brand that is designed for the exact characteristics of the scanner...

If Not SIS, you can find the boolean logic for 2oo3 voting logic in a Google (images) search. There's not likely a commercial product because such basic logic that can be implemented in any low end PLC.

If you change the range of a 4-20mA transmitter, then the input range of the receiver, the PLC, DCS, indicator, controller, recorder analog input, must be modified to reflect the change, unless the TT is Foundation Fieldbus. Not changing the receiver range will give a 20% error at the high end...

By definition, the MODBUS specification declares that a holding register or input register is 16 bits. MODBUS does not define the format of the data in a register, it defines only the register size, 16 bits. A 32 bit floating point value requires two 16 bit registers. A 17 bit data word...