Technical Note #631 Remote Access to a MITSUBISHI PLC using a VT-MODEM Abstract: This document explains the procedure for dialing and establishing communications with a MITSUBISHI MELSEC FX-16MT or FX-64MT PLC using a SIXNET industrial modem (VTMODEM-#). FX-16MT from MITSUBISHI can be controlled remotely via telephone wiring using a SIXNET industrial modem. The FX-16MT can be programmed to perform its poll of I/O modules or other devices through the phone connection. Software Used: · · · MELSEC MEDOC v2.30 SIXNET VT-MODEM Setup Wizard v1.15 Windows 2000 OS Hardware Used: · · · · · · · (1) PC with a serial port connection to a VT-MODEM-1 via the VT-CABLE-MDM (1) MITSUBISHI MELSEC FX-16MT PLC (an FX-64MT will also work in this application) (1) VT-MODEM-2 connected to the MITSUBISHI MELSEC FX-16MT PLC via the VT-CABLE-MDM cable. (1) BEI’JERS SC-09 RS232/RS422 converter (DB9 Female RS232 to DB25 Male RS422) (1) Male-to-Male straight-wired Gender changer (used for the connection between the VT-MODEM-2 and the BEI’JERS converter cable) (1) VT-CABLE-MDM (VT-MODEM-1 to PC) (2) RJ11 telephone cables Cable Pin-outs: BEI’JERS SC-09 with gender changer DB9 Male to PC (DTE) DB25 Male to 16MT è 1 8 CD ç 2 3 RD out è 3 2 TD out ç 4 20 DTR 5 5 GND ç 6 6 DSR è 7 8 CTS out ç 8 7 RTS in All other pins are not connected VT-CABLE-MDM DB9 Female to PC (DTE) 1 2 3 4 5 6 7 8 9 ç ç è è ç è ç ç DB9 Male to modem (DCE) 1 DCD out 2 RD out 3 TD in 4 DTR in 5 GND 6 DSR out 7 RTS in 8 CTS out 9 RI out SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected] TN631.DOC PAGE 1 OF 8 REV: AUGUST 2000 PC and VT-MODEM-1 Windows Setup: Note: A SIXNET VT-MODEM-1 was used during testing. However, most internal PC modem cards will function properly as the dialing modem in this application. To configure Windows to recognize the VT-MODEM-1, go to Start à Settings à Control Panel à Phone and Modem options. Next, go to the Modems tab in the Phone and Modem options window, and then click on Add… Next, check the “Don’t detect my modem; I will select it from list” box and manually select “Standard 28800 bps Modem” from the modem type list. Refer to screen shots 1 and 2 below for details of how the modems were configured. Screen Shot 1 Screen Shot 2 Configuring the Software: · MELSEC MEDOC v2.30 - Using MELSEC MEDOC go to Start à Open and open the project containing the correct PLC (See Screen Shot 3). Next, go to Transfer à Setup and set the baud rate for 9600, 7 data bits, Even parity, 2 stop bits (See Screen Shot 4). SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected] TN631.DOC PAGE 2 OF 8 Screen Shot 3 Screen Shot 4 Configuring the Hardware: VT-MODEM-1 – Connect the VT-MODEM-1 to the PC via the VT-CABLE-MDM. Load the preconfigured 16MT_64MT_vt1.6ms available on the latest SIXNET CD and in the modem section on www.Get2Support.com by pressing the “Open Configuration File” button located in the “Read Configuration” window in the VT-MODEM Setup Wizard. Using the SIXNET VT-Modem Setup Wizard, choose VT-MODEM-1 in the first window. Select the appropriate communications port (in this case COM 2) with Hardware flow control. Configure the Baud Rate for 9600 with 7 data bits, Even Parity, and 2 stop bits (See Screen Shot 5). SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected] TN631.DOC PAGE 3 OF 8 Screen Shot 5 In the “Modem Parameters” setup window select “None” in the Flow Control drop down list. Finally, write the configuration to the modem by clicking on the “Write Configuration to the Modem” button (See Screen Shots 6 and 7). Screen Shot 6 · Screen Shot 7 VT-MODEM-2- Configure the VT-MODEM-2 the same as the VT-MODEM-1, or if available on your CD or in modem section on www.Get2Support.com, use 16MT_64MT_vt2.6ms. To enable the Self-Dialing feature in the VT-MODEM-2, check the “Enable Self-Dial” check box in the “SelfDialing Parameters” window in the VT-MODEM setup Wizard and enter the phone number of your destination modem in the First Number text box (in this case 24). Use of the other features are optional, but in this case the ID message “VT-MODEM-2” was used to demonstrate the ID message feature (See Screen Shot 8). Load the configuration to the modem. SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected] TN631.DOC PAGE 4 OF 8 Screen Shot 8 Connecting the Hardware: · Phone Connections- The two modems were connected to an internal analog phone system through their Line RJ11 jacks using standard RJ11 telephone cable. · Connecting the modems to the devices- Connect the VT-MODEM-1 to the computer’s communications port 2 via the VT-CABLE-MDM. Connect the VT-MODEM-2 to the DB25 Female Programming port via the straight-wired male-to-male adapter and the BEI’JERS SC-09 RS232/RS422 adapter cable. Establishing the connection: To establish the connection, the Windows program HyperTerminal Should be used. (Note: To perform this step successfully the MELSEC MEDOC software must be completely closed.) Start HyperTerminal, and enter a name (In this case the name is FX_16MT). In the “Connect To” window select the COM port that the VT-MODEM-2 is connected to on your PC (In this case COM 2). In the “COM 2 Properties” window configure the Baud Rate for 9600 with 7 data bits, Even Parity, and 2 stop bits (See Screen Shots 9 and 10). SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected] TN631.DOC PAGE 5 OF 8 Screen Shot 9 Screen Shot 10 In HyperTerminal’s main window issue an AT command to verify that the PC and Modem are communicating. The Modem should send back an “OK”. Then issue an ATDT# command where # represents the phone number of the VT-MODEM-2 connected to the PLC. When the modems connect HyperTerminal will display a “Connect 9600” message (See Screen Shot 11). Save the session and close HyperTerminal completely. Screen Shot 11 SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected] TN631.DOC PAGE 6 OF 8 Open the MELSEC MEDOC project that was previously configured for this application. Go to Transfer à PLC à Medoc>PLC. When the PC and PLC begin to transfer the program a Transferring status gauge will appear. When finished a “Transfer Completed” message appears (See Screen Shot 12). Screen Shot 12 To disconnect the modems close MEDOC completely, and open the saved session of HyperTerminal. Type “+ + +” (three plus signs) wait for the modem to send an “OK”, type “ATH”, and then press the Enter button. When the modem sends back an “OK” then the modems have disconnected (See Screen Shot 13). Screen Shot 13 SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected] TN631.DOC PAGE 7 OF 8 Establishing a connection using the Self-Dialing feature: To establish remote communication between the PLC and MEDOC software using the Self-Dialing feature, a dial-up connection must be initiated by the remote VT-MODEM-2. The feature is initiated by activating a discrete input to the “From PLC” input on the VT-MODEM-2. To verify that the connection is established and the ID message is sent successfully, use HyperTerminal to monitor the incoming data at the answering modem. In this case the VT-MODEM-1 was used as the answering modem. To prepare for the connection, start Windows HyperTerminal (see previous section). To initiate the Self-Dialing sequence, apply a continuous supply of 10-30 VDC to the “From PLC” input on the VT-MODEM-2. When the Self-Dialing feature is enabled, the Power LED on the modem should blink rapidly. You should see the following messages in your HyperTerminal window: Ring, Connect 9600, and ID String (See Screen Shot 14). To hang-up the connection, disconnect the 10-30 VDC on the “From PLC” input on the modem, and the modem will hang-up automatically. Screen Shot 14 Conclusion: This test successfully established communications between a PC and FX-16MT or FX-64MT via SIXNET industrial modems. SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected] TN631.DOC PAGE 8 OF 8