Serial Vs POM and TCP/IP for modbus

[Ingeniero]

thanks BobO,

Bigger turbines run at 3600 RPM. They often use a 60 tooth wheel which means the HZ reading and the RPM reading are the same. The speed sensor sees 3600 teeth or pulses per second for a 60 HZ single shaft machine.  Smaller turbines turn faster and so need higher HZ readings. Does your counter perform at 3600 HZ to 7000 HZ.  The signals are very low VAC at low RPMs and I have seen 30 VAC at full speed. Lots of variables on the voltage, pickup, sensor gap, speed, tooth size but that's a range. there are some work arounds for poor low speed detection, timers etc.

glad you are testing this, who knows where this leads. I am open minded about using your counter card.

generally filters are a nono, a filter delays response to good signals, defeating the purpose of fast loops and can causes control instability.

[BobO]

Don't even need the counter card, just fast onboard inputs.

I think we'll pick up down to 5v or so. Our input counter operates at 250k. The only decision you have to make is whether counting or timing is the better path to frequency. Everything you are describing is relatively slow, so timing is probably better.

Assuming you can get the input to pick up, BRX was built for this.

[Ingeniero]

 https://www.woodward.com/-/media/publication-assets/technical-manual/2019/4/18/19/58/82020.pdf

Edited link


The link is too a PDF about the woodward 2301A engine controller. See page 9 for the settings for speed.

These controllers are on lots of different engines, now they are coupled with PLC's to interface with breakers, pollution control and HMIs. Its just a matter of time/price till the control function is moved to the PLC also.

[Ingeniero]

the ecomlt is sold out till almost june.

the serial POM BX-P-USB-B  says good for programming with Domore software. Does that include monitoring logic in the PLC and programing?

[BobO]

the ecomlt is sold out till almost june.

the serial POM BX-P-USB-B  says good for programming with Domore software. Does that include monitoring logic in the PLC and programing?

I think we had a large order last week. I seriously doubt they will be out of stock that long.

The USB POM fully supports Do-more Designer.