The features of PC is P4-2GHz, 512 MB Ram, 20 GB IDE HD, 3COM USRobotics 56k Modem and Windows 2000 Professional O/S.

PLC is Modicon. SCADA program is Wonderware 2000 FactorySuite.

i connect successfully with RS232 cable to direct PLC.

But, actually i need DialUp connection because the plant is 350km away from control & command centre.

At first step; i connect to PLC's USRobotics AutoAnswer Modem (at COM1) with Hyperterminal. (This is good!)

Second step; i close HyperTerminal, it asks me "line is hang-on or close down". i choose hang-on normally.

Third step, Modicon Modbus starts to read data on COM1.

After that "Cannot open port COM1" or "Port is used from another program" appears on the screen.

(i think that, i need some Hayes commands but unfortunately i dont have.)

Or do you have any solution to solve this problem?

Regards...

Ogun OZPINAR
System Analyst
Birlesik Oksijen Sanayi A.S.
Gebze Org.San.Bol. 300.sokak Gebze / KOCAELi

* Tel:+90 (262) 751 01 00 '162 ext.
* Fax:+90(262) 751 01 15
* e-mail: [email protected]
[email protected]
* web: http://www.bos.com.tr
http://www.boc.com.tr

 

Hey,

I don't know how to enter commands (hayes) before starting modbus protocol (may be Modbus ascii instead of RTU).
But then hayes command to dial a number is
ATDT phone number.

Good luck

What is the Modicon PLC used ?

Reagrds
Jérôme

 

Are you trying to establish a dial-up connection to the PLC's modem with HyperTerminal and then use the port your PC modem is on (COM1) to send/receive data from the HMI application?

While we did this often with DOS, I've not be been succesful doing it in WIN32 OS's. WIN doesn't allow a program to use a port that was openned by another program until the first program is closed down.

Your best bet is NOT to use HyperTerminal to make the connection. There should be a dial-up function in the HMI for this purpose.

Good luck.

Zvi