Flex727

It may not help, but I would pull the battery for an hour and try again. I would also attempt to load a blank project if it gets to a state to accept software.

It doesn't really require a remedy, but the remedy would be to use the Vision or UniStream product lines.

Not sure how that would work since it is threaded and hyperlinked. There certainly is a "Find" function (tab labeled "Search") though I will agree that it's somewhat incomplete. What information were you looking for that you couldn't find?

I generally just shift the entire table down one row then write to the top row every time. No need to keep track that way and it's easily accomplished in a single ladder rung.

There is no reason to use floating point numbers in this situation. No digital computer or PLC can handle floating point numbers perfectly and it's best to avoid them when possible. This is due to the conversion from decimal to binary and then back to decimal. Without infinite precision, which is of course impossible, there will be rounding errors which can be significant. In your case, use integers (add 1, not 0.1) and display the number with one decimal place. If you need to perform calculations, just keep track of where the decimal place is and make sure it matches on all the other numbers in the calculation.

I should point out that the OP's main question here is why are the two different motor sensors being responded to differently by the PLC. I think a partial answer is that with a 10ms response time on the input and probably 4-10ms scan time, aliasing will play a large role in detecting the pulses accurately. I would bet if you put an oscilloscope on the two sensors you would see a small difference in the pulse width which can be magnified by the PLC response due to response time and PLC scan time interacting.

Here is kratmel's suggestion visualized: This really is the best way to accomplish what you're trying to do.

What is your PLC scan time (SI 0)? What I/O module are you using? I presume since it is I 4, then it is one of the Snap-In modules? Also, why are you counting both rise and fall of I 4? One can't happen without the other.

In all likelihood the bit goes from 0 to 1 and back to 0 too fast for you to see. The Function in Progress bit is how you check to see if communication is active.

You can check the PLC Ethernet address in UniApps (touch and hold the upper right corner of the PLC screen).

Split this off into its own topic.

Does your PC have both a wired Ethernet connection and WiFi? If so, it's easy to confuse the two settings and get the subnet wrong. Make sure your PC's WIRED Ethernet connection is on subnet 192.168.0.xxx.

Try a crossover cable or get an Ethernet hub or switch. Can you Ping the PLC from the PC?

Moved to the correct forum.

No. I don't know what caused your pumps to start working, but this is not the reason.

That is just something VisiLogic does when it's online with the PLC. It's not actually following the logic of your program - it is only checking the value of each operand and displaying it on the screen.

Thanks! That is good to know.

Actually, I was more concerned about a customer's network than I am about mixing protocols within a Unitronics PLC network.

Search your project for MB 10. If there is an MB 10 coil elsewhere it could be overriding. The other likely possibility is that this ladder net is in a subroutine that is not being called by the Main Routine.

@Gabriel Franco, I have often wanted to do that in certain situations, but always worried that the UDP protocol and TCP protocol might not coexist well on a customer's network that is using TCP. Are you aware of any issues with that?

It seems like you understand things well. Based on your question I am assuming you are using MODBUS TCP. If you have only a few seconds available between readings then you will need to use multiple sockets. For simplicity, I would use 3 sockets (leaving the 4th for communication with VisiLogic or a SCADA system, etc. Each socket will be used to connect to two slaves. For each socket, you will need to connect to one slave, exchange data, disconnect from the slave, connect to the second slave, exchange data, disconnect, and repeat. The only trick is to allow plenty of time to connect and disconnect, as it can take some time to complete that function.

Moved to correct forum.

When I Google "MJ10-22-CS26 pinout" I get lots of hits. Did you try that?

It's very simple, if a bit tedious. In UniLogic, go to PLC Communications, Protocols, MODBUS, Masters, Panel Ethernet, Add New Slave. Once you do that you can add new operation which includes assigning all the addressing that's compatible with the Vision PLC. The UniLogic Help file tells you everything you need to know - check it out.

You said you have a competent IT person at your disposal. Isn't that a question for him (or her)?