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Modbus is NEVER plug 'n play. Never ever. Modbus is always a project. A Modbus slave is pretty passive. The slave just executes the tasks that the Master tells it to execute and replies with a confirming message. So if you changed PLCs and can not talk to the same temp scanner as before...

And your question is ?

You could start with an actuator designed to be controlled by a potentiometer. Honeywell's Series 90 Modutrol partial turn rotary motor/acutators are controlled by a 135 Ohm pot. Of course, the challenge will be whether the actuator - fits and mounts - is fast or slow enough - has enough torque

I can't. You can't. Too little data. 0-2500mmWC is the pressure drop across a primary flow element, it's not a flow rate. You need a basic flow rate to convert to another flow rate. 0-2500mmWC represents some calculated flow rate, depending on the design inlet pressure, design...

> when testing like this you should remember: Exhaust T/Cs are biased from their “raw” (CJ compensated) value before being used in the temp control and protection algorithms, so the values you see on the display don’t match the incoming, CJ compensated values (post #6) Sounds like a major...

1. When a thermocouple reads low, it can be due to cold junction compensation not being enabled or being measured for that circuit/input/T/C. If the cold junction measurement is made locally in a remote terminal junction box, where copper wire is then used for the final connection to the...

Software rarely has Modbus maps for the equipment; the manual for the device normally has the Modbus map, if it's not separate communications manual. The 735 is a GE Multilin product. The 735 / 737 Feeder Protection Relay Instruction Manual has the Modbus memory map. The manual is listed...

Can't change a node ID address value that is not assigned to a Modbus register.

What is a ADPRW or a ddrvi instruction? That's not part of conventional Modbus terminology.

Some of your questions are answered in Kepware's Youtube tutorial here, starting at 5:00 minutes:

That's a 62% error. The K-Factor is the number of pulses for every unit of product volume passing through the meter. You're using the wrong K factor to calculate the flow rate.

I thought I'd skim read the paper but Google can't find it. So I'm clueless about what a fixed speed rotation turbine meter is. Why would anyone mess with an efficient means of flow measurement for clean liquids, ie, a turbine meter. Probably a marketing white paper trying to seduce the...

No, not everything is OPC UA. I know of two places using a version of iFix that is still running OPC DA V2 because the mandatory Microsoft update for the DCOM security component is approaching in March.

Except for repair instructions on - replacing the entire electronics unit - exchange of transducers, either under pressure or depressurized - replacing the clock battery there is no troubleshooting information in the manual. So either you have boat anchor or you can get in touch with Krohne...

profibus, is each status/command (such as start, stop, running etc) its own input, or is the profibus signal itself one input? as it is only terminating into one card? A master asks for data, the slave provides the data. Then the master moves onto the next slave and asks for data. If the...

if a PT reaches a High alarm level of 5 bar or say 18mA, is this set point then converted into a digital input to the system/graphics/HMIs where ever it is displayed or logged? No. The transmitter sends its process variable (PV) to the DCS via analog (4-20mA) or digital (FF, Profibus, Modbus)...

Link URL corrected. Sorry for the bad link. Suggestion that you sum up your technical question in the subject line. Some Fora delete threads begging for help without any statement as to the type of problem or what field or category.

In post #3, the figure labeled 134 is the analog/discrete I/O connector, an 8 pin M12 connector. Fig 134 shows which pin is which. The figure labeled 004 is a 4 pin transformer coupled Ethernet connection on the 4 pin M12 connector. Just looking at the box tells you the 8 pin M12 is on the...

Honeywell has traditionally not made the documentation for their DCS systems public. The C200 is briefly described on this page but the support buttons provide no links to documentation...

Lots of OPC troubleshooting info here: https://www.opcti.com/opc-dcom-five-tips.aspx