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My bad. Banner gateway NID is NOT the Modbus slave node ID. The Modbus slave node ID setting in the Banner gateway is SLID, not NID.

Sorry, no A-B experience. 1) If the master times out, it means the Banner did not reply. If you addressed the wrong slave node, then the Banner would ignore the message. Are you sure you're addressing the correct NID (network ID) value in the gateway? The left rotary switch sets up the...

You bought an RS-232/485 converter for a reason. Presumably the S7 has a Modbus slave port that talks on RS-485. What kind of cable? Most Modbus RTU RS-485 links are 2 wire, half duplex. If yours is too, use twisted pair copper wire cable and wire + to + and - to -, or A to A and B to B...

I can't post a copy or a link to it, it's not in an electronic format. I typed the two pages that were relevant to the discussion from the paper copy on my bookshelf. The book is over 25 years old and was published in that era before electronic (pdf) files were common formats. Occasionally...

A Modbus-enabled slave, the drive your case, will reply to a properly addressed query/request from a Modbus master. So your microcontroller has to be prepared to receive the reply and deal with the data as soon as the request is finished. Apparently, your micro controller does not support...

If the oscillations are not due to Smart_S's reasons or a defective sensor, but are due to a PID loop chasing its tail, then you can reduce the oscillation due to the PIDs aggressive tuning. First, see if you can't configure the range of the temperature units associated with the analog input...

The thermocouples are drifting. Drift is caused by chemical change to the thermocouple junction. This is referred to in the literature as "inhomogeneity", meaning the junction is no longer an combination of its two 'pure' alloys, Chromel {90% nickel and 10% chromium} and Alumel {95% nickel...

1). All the serial parameters need to match identically on both ends. - baud rate - word size (8 bits) - parity (even?) - stop bit (1) 2) You need to know the slave node ID of the flow meter, its unique network bus address, an integer value from 1 to 247. E&H calls it the fieldbus...

Honeywell published a textbook on its industrial flame safeguard controls. The text below is the part of section on UV flame detectors. Flame Safeguard Controls: A Honeywell Textbook 71-97588 (1989) pages 95, 96 Ultraviolet UV Flame Detectors Operation Ultraviolet flame detection...

Convert the motor's 0-5k ohm with a parallel resistor to something close to the standard 0-1k transmitter input. Put a 1.2k ohm resistor in parallel across the variable 0-5k ohm and you'll get a variable 0-968 ohm output. That's close to full resolution of the 0-1k input.

Why are you bothering with a silly process control project when you've achieved a miracle in physics and should be wrangling for a Nobel Prize? Absolute zero is 273.15° but you've achieved -1,000 Deg X! Ordinarily engineering units are critically important in any engineering or...

A 2 wire RTD will ALWAYS have some offset error due to the resistance of the copper connection wire. The longer the wire, the higher the resistance, the larger the error. For practical purposes, that error can be eliminated with a 3 wire RTD. Get a 3 wire RTD and use the 3rd wire. The 3rd...

Thank you, Walt, for the succinct summary.

> Is the pressure measured by the gP transmitter going to be affected by the density of the oil? It depends. In context of your discussion, if the volume of oil in the tank is constant (no leaks, no removal, no addition), the changing temperature changes the density and a pressure...

I have a copy of an old 1993 API 21.1. I've searched it and can't find that calibration interval recommendation of 3 months. I recall seeing a draft of a proposed revision about 5 years ago and don't recall seeing it then, but I haven't been involved enough to warrant getting the most recent...

In my somewhat limited experience, calibration intervals for custody transfer are agreed upon by both parties. See the measurement manual, pages 27 & 28 at http://tinyurl.com/mwz55zz to see an example of calibration frequencies. In industrial and safety applications, service conditions...

Presumably the 0-500mbar DP transmitter is used over the upper range of 150 - 500 mbar. The 500 mbar transmitter DP turndown is 500:150 or 3.3:1. That would correspond to a range of 100% max flow rate at 500mbar to 54.8% flow rate at 150mbar. (square root of 30% (150/500) DP is 0.548 or...

Honeywell UDC 2800 https://www.lesman.com/catalog/product/view/id/13062/s/honeywell-udc2800-1-4-din-digital-single-loop-or-limit-controller/ Pick the 2nd input for an analog remote setpoint, or Pick Modbus RS-485 if a Modbus RTU master can write a remote setpoint to the controller (a Modbus...

Books like "Electric Motor Control" by Stephen L. Herman are available new or used from internet sites like Amazon. Be aware of numerous editions.

Pressure transmitters are generally rated to about 125 Deg C body temperature at 85 Deg C ambient. The connection to the process through the impulse tubing is deadheaded; there is no flow through the impulse tubing. Without flow, there is a relatively high degree of cooling with minimal...