Saturday, January 22, 2011

Getting Started with the PLC_DIAL





To connect PLC and Serial DDE Server over the telephone line you need 2 modems, one at each side and the following step must be performed:
1. Configure the Remote Modem, modem that used at PLC side. This modem must be able to save its configuration to its non-volatile memory. To configure remote modem do this following steps:
• Connect modem that you will use as a remote modem to computer.
• Set Initialization String and Save Setup String for remote modem with ‘Remote Modem/Settings’ command. If you do not know exactly what strings you need, you can use default strings.
• Initialize modem with sending Initialization String and Save Setup String to modem with ‘Remote Modem/Initialize’ command.
• Remote modem is configured now and you must disconnect it from computer and connect to PLC and telephone line.
You must configure remote modem once, you can change the configuration of remote modem when you need. The remote modem can not be re-configured over the telephone line.

2. Configure the local modem.
To configure the local modem you have to do the following steps:
• Connect modem that you will use as a local modem to computer.
• Check from your modem’s manual and set Initialization String, Hang up String, Dial Prefix and Suffix, Connect and Fail Strings for local modem with ‘Modem/Settings’ command. If you do not know it exactly what string you need to select, you can use default strings. Configure the local modem to automatic answering mode if PLC can call to PLC_DIAL.
Actually you have to configure the local modem only once, but you can also change the configuration of local modem when necessary.
3. Initialize the local modem and dial to the PLC or wait for a call from PLC. You have to do the following step to initialize the local modem:
• Initialize modem by sending Initialization String to modem with ‘Modem/Settings’ command.
• Dial to the PLC with Modem/Dial command or wait for a call from PLC in automatic answering mode.

4. When connection is established you have to close the communication port used by local modem, without hanging up the modem, and start the DDE Server.
5. When the DDE Server is started you can close the PLC_DIAL with ‘File/Exit’ command.



Newer Post Older Post Home

You may also like these ebook:

Get Free PLC eBook directly sent to your email,
and email subscription to program-plc.blogspot.com




We hate SPAM. Your information is never sold or shared with anyone.

Your Email Will Be 100% Secured !