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PC-Modem-PLC connection

This tutorial is designed to cover the configuration and connection between PC and PLC using modems.
I. Wiring
Attention!: Be careful to identify the PLC and modem cable side

II. Modem Configuration
1. Set switches 5 and 6 to ON
2. Switch on the modem power 24V, there must be a free boundary between 0 and 24v (5V)
3. Connect Multiway Terminal mode 9600bps, 8, N, 1
4. Type: - AT & F [Cr] Load the default settings - AT & D0% E0 [Cr] Force the DTR signal - AT + MS = 9,0,0,9600,9600 [Cr] Modulation V32 - AT! RS: 5, N, 8.1 [Cr] Lock format 9600.8, N, 1 - AT & W [Cr] Save

The Modem Gener GENINDUS are already configured and factory. You can view the configuration by typing conf [Cr]
5. Repeat for the second modem

Note: All above commands are now incorporated into Multiway since version 6.8 

III. Configuration Sysmac-Way RS232C port.
1. Set switch 5 to OFF (in RS232C Port config. Custom). 
2. With the help of CX-Programmer, configure the port as 9600.8, N, 1, Host Link 

3. Transfer the parameters in the PLC

IV. Remote connection Sysmac-Way RS232C port 

1. In Cx-Programmer, select the protocol SYSMAC-WAY format 9600.8, N, 1 

2. Configure the modem as follows:

3. Connect

V. Toolbus configuration port RS232C
1. Set  switch 5 to OFF (in RS232C Port config. Custom). 
2. With the help of CX-Programmer, configure the port as 9600, 8, N, 1, Toolbus

VI. Toolbus remote connection to the RS232C port 

1. In Cx-Programmer, select the Toolbus protocol format 9600.8, N, 1  

2. Uncheck the automatic detection
3. Configure the modem as previously
4. Login
Note 1: The mode 'Auto' PLC (switch on 5) prepares to receive the automatic sequence of auto-detection and at variable speeds. This method is not applicable when using modems. It is therefore imperative to use the Custom Toolbus. If the installation does not allow it, it will be necessary in this case to manually send a command to the modem dialing, and then, once connected, use Cx-Programmer with automatic detection enabled.
Note 2: In the case of long distance communications, increase response time in the window of network parameters of CX-Programmer. If despite this, problems remain, increase the inter-digit time (S26) modem Genindus (problem caused by satellite transmissions)

VII. Troubleshooting

The PLC does not send the numbering command

Cause Solution
The COM port is not free in ASCII mode - Change the settings of serial port
- Check the position of switches on the front of the PLC
TXD function number is another function  Transfer to the PLC functions extended 
Com port number doesn't work Change the TXD destination  (# 0000, # 0001 ...) 
The character number to send is 0 Add a # before the TXD operand instruction
Absence of RTS (CS/CJ/CP1 series)  Shunt pins 4 and 5  RS232C cable

The transmission control is automatic, but the modem does not receive anything

Cause Solution
The command physically fails Check the cable

The modem receives the order but does not carry out the numbering 

Cause Solution
The DTR modem signal is absent Disable management DTR with the command AT & D0
The number is not working(no response after 3 calls) Reset the modem
Tone not detected Delete W from the number command
TXD function is always running Add a @ to the TXD function

The remote modem is not answering

Cause Solution
The S0 register is 0 (number of rings before answering) change the S0 register for the remote modem with the command ATS0 = 2

The communication is remote, but the PLC does not respond

Cause Solution
The PLC doesn't understand the command - Refer to the remote modem command AT HyperTerminal with the desired format and then save with AT & W
- Set the asynchronous modem (AT & Q0)
- Check the driver SG cable - make sure it meets local
The PLC has not received a character at the end of frame (* or CR) Add the proper separator (if the numbering is generated by a machine in ASCII free mode)
The slave number does not match that of the PLC Change the RS232C port


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Created 2009-08-18
Modified 2009-08-26
Views 12627


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