Dial-Up Modem Communication

Owned by CIMON (Unlicensed)
Mar 25, 2024
3 min read

Outline

This function is to use the public network for a long-distance network.

 

Modem Specifications

In case of modem communications, it is required to use the modem complying with the recommendable specifications for reliability.
According to the performance of a modem and the state of a public network, the case that a line is not linked or the case that a link is cut off while exchanging data may occur.

 

· Baud Rate

Over 14400 bps

 

 

· DTE Interface

CTS / RTS Flow Control

 

 

· Command

Hayes Exchange AT Command

 

 

· Error Correction

Error Correction Function while Sending data

 

 

· Controlling carrier

Controls to send carrier

 

image-20240325-005645.png

 

Modem Link

  • Order of Modem Installation

  1. Use RS-232C interface cable to connect a computer link module and an external type RS-232C modem.

  2. Connect a RS-232C interface cable to the RS-232C port of the computer link module and DTE link terminal.

  3. Connect the telephone line of a public network to the line terminal of the modem.

  4. If there is a telephone set, connect the phone terminal of the modem with the telephone set.

  5. Turning on the power for the PLC and the modem, make sure the modem is initialized.

 

 

  • Parameters Setup for Modem Communications

As all modems provide the functions discriminated by manufacturers, the parameters for modems are to be set up.
The modem operation mode is set up with the initialization command of a modem. The same operation mode is to be set up for the two modems used.

  1. Select the menu to run the graphic loader(CICON).

  2. Select menu to set up communication parameters such as communication channel, modem, baud rate, parity bit, stop bit, station number and communication type.

  3. If a modem is set up, it will be available to set up the initialization command. Enter the modem initialization command set up.

  4. Enter the default value for basic parameters such as station number, communication method, parity bit, stop bit and initialization command. Baud rate is to be set up according to the maximum rate of a modem.

 

CICON Link Service through Modem

This function is used to write programs, to download user programs, to debug programs and to monitor in the network system that a PLC is linked through a computer link module by remote control without moving the physical link of the CICON.

 

image-20240325-005755.png

 

When a master(CICON) is far away from a slave(PLC), using the function of the modem link, a PLC can be linked with the CICON.
As it is available to link with the PLC located at the place difficult to access as well as to link with a PLC at a long distance without moving the contents of the PLC, using the communication service of the CICON, programming is easy after installation. This function reduces the time and efforts taken when installing and modifying.

 

  • CICON-Modem Link Method

This service is to link a computer link module with the CICON through a modem. After the CICON is connected with a telephone, the order of remote link is as follows.

  1. Select the menu to set up a dial-up modem and the CICON protocol as the parameters of a computer link module. And select the menu to set up baud rate.

  2. After connecting a modem with a computer link module and a telephone wire to the modem, turn the power on.

  3. Select the menu to initialize the modem.

  4. After the CICON is run, select the environment setup in the tools.

  5. Select the dial-up and set the values for other parameters.

  6. If the CICON dials, the message that the dial-up link is completed will appear.

  7. It is available to control the PLC at a remote place.