I am using Modsoft 2.62. The node is set to station #2 via the dip switches on the processor. I have set the dip switches for communication (RS232 via Modbus port) for 9600 which is the factory default. The same is set in the software. The toggle switch on the processor is set to DIP not MEM (I tried it both ways). I am using a cable which I know works and on COM1 on the PC.

When I power up the processor, everything on the LEDs indicates normal (green light, ready light on, modbus plus light flashing) When I try to go directly on line the processor the software comes up with an error message 199, PLC timed out, review processor addressing. Yet I get the Modbus light flash as it's trying to communicate with the processor and PC. I have tried changing the addresses on the DIP switches and in the software but I just can't seem to get online.

Any suggestions... I'm fairly new to Modicon, I usually use AB PLCs but I need this one going.

Thanks

 

If the Modbus LED is flashing it means a valid Modbus transaction occured. It may well be that you are not setting the address dip switches properly. I have never used the Modsoft software, but all the other Modicon PLC programming packages I have used (4 in total I think) had some kind of function to check the Modbus network and report back any slaves it finds out there. You might try that.

 

This may NOT have anything to do with your problem, but something to check anytime Modicon PLC act deaf. Different versions of Modsoft and different Modicon PLC have different demand for control signals (mainly DTR/DSR). So a cable without DTR/DSR connected that works with one model may NOT work with another. So just make sure your DTR/DSR and RTS/CTS are either looped-back at both ends or run through the cable properly.

- LynnL, www.digi.com

 

The address of your PLC (node #2) must match the address in your Modsoft port configuration for Modbus. You can change either one, the default is #1.

What type of computer and OS are you running? Modsoft is DOS based and may not properly access the serial comm ports on Win98 and above.

 

I had the same problem with communication using MODSOFT with PLC Modicon MOMENTUM (MICRO or QUANTUM). That error message (199) only shows that there isn`t properly communication.

MODSOFT is a DOS based programm but You probably worked in Windows95,98,NT. Modsoft obviously doesn`t have internal driver for MODBUS communication throw Windows. Try start MODSOFT in plain DOS (without starting Windows). It works.

p.s If You use MODBUS PLUS network That problem doesn`t appear.

 

<p>Hello Phil,

<p>> I am using Modsoft 2.62.

<p>What OS are you running Modsoft under?

<p>> The node is set to station #2 via <br>
> the dip switches on the processor. I have set the dip
> switches for communication (RS232 via Modbus port) for 9600 <br>
> which is the factory default.

<p>I assume that you also set the Stop bits=1 , and the Parity=Even, and
the Mode=RTU.
So to summarize the DIPs should be;
<pre>
1 2 3 4 5 6 7 8
OFF| ON |ON |ON |ON | don't matter
</pre>
<p>The Modbus Plus Dips, for address=2 should be
<pre>
1 2 3 4 5 6 7 8
ON |OFF|OFF|OFF|OFF|OFF|OFF|OFF
</pre>
<p>> The same is set in the <br>
> software.

<p>So the Softare should be set for;
Address = 2
Baud = 9600
Parity = Even
Mode = RTU

<p>> The toggle switch on the processor is set to DIP<br>
> not MEM (I tried it both ways).

<p>OK

<p>> I am using a cable which I <br>
> know works and on COM1 on the PC.

<p>Does this mean you have used the cable on another Modicon 984 PLC or
that you have used it on some other PLC?
If the cable does not have the correct pin-out it won't work.

<p>Bradley G. Hite <br>
Intertech Inc <br>
mailto:[email protected]<br>
Teaching Practical Skills for a Technological World

 

Also note that if you are using any NT based operating system (NT, Win2K, WinXP) on your computer, Modsoft will not work with serial port comms.