Technical Note #612

Technical Note #612
VT-MODEM Interfaces with the Allen-Bradley SLC-5/04 PLC using
Rockwell’s RSLogix 500 & RSLINX Lite Software
Abstract: This document explains the procedure for interfacing a SIXNET Industrial Telephone
Modem with an AB SLC-5/04 controller and a computer running the Rockwell RSLogix
500 programming software and the RSLINX communication software. This set up will
allow a remote computer to go on-line with a SLC-5/04 via a telephone modem connection.
Stork Gamco, Inc. has created the following guide for interfacing a SIXNET Industrial Modem
(VT-MODEM-1) with an Allen Bradley SLC-5/04 PLC and Rockwell’s RSLogix 500
programming software and RSLINX communication software. This telephone modem interface
provides long distance communications between the operator and the PLC. Diagnostics and
troubleshooting can now be done from hundreds of miles away. This saves time and money
because problems can be corrected or configuration changes made without traveling to the PLC.
Hardware and Software Used:
•
•
•
•
•
•
•
SIXNET Industrial Modem (Part Number: VT-MODEM-1)
Serial cable (Part Number: VT-CABLE-MDM) (Incl. with VT-MODEM-1)
SLC-5/04 CPU with Channel 0 serial communications port (i.e. 1747-L541)
Rockwell RSLogix Software v2.10.12
Rockwell RS LINX Communication Driver v2.00.97
PCM/CIA modem card (Megahertz Telephony Modem; CC-XJ1560 Fax-Modem)
Analog phone line connections at both ends (digital lines may not work). The phone line at
the SLC-500 end must also be a direct-dial number from the outside (Stork Gamco, Inc.
recommends that if possible the analog line should not be routed through a PBX system).
Receiving Modem (SIXNET VT-MODEM-1) Setup Procedure :
Use Window’s HyperTerminal to communicate to the modem.
Note: For information on how to use HyperTerminal, please consult the SIXNET VT-MODEM
online help guide located on the SIXNET CD in the Product Catalog.
Settings can be changed by connecting the straight through cable, which comes as part of the Industrial
Modem package (VT-CABLE-MDM) to the serial port on the modem and the serial port of the
computer (i.e. serial port COM1).
Important: Choose the baud rate that matches the PLC or other device that will be connected to
the modem. Anytime a setting is saved using &W0 or &W1, the RS232 baud rate is memorized
SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected]
TN612.DOC
PAGE 1
REV: MAY 1999
by the VT-Modem. The saved baud rate will be used for future communications with any
attached device that does not initiate communications with the modem (such as most PLC’s).
To check communication, type AT <Enter>. OK should appear.
To Set Up Modem:
Type In: AT&F<Enter>
Type In: ATS0=1<Enter>
Type In: ATS46=136<Enter>
Type In: AT+MS=11,0,9600,9600<Enter>
Type In: AT&W0&W1<Enter>
Type In: AT&V<Enter>
- This sets the modem to factory defaults
- This set the modem to auto-answer
- This turns off data compression
- This forces a 9600bps modem to modem speed.
- This save changes to both profiles
- Use this to verify changes
SLC 5/04 Controller Channel Configuration:
Whatever PLC program is running in the processor is not important; however the Channel 0 (system and
user) port must be configured properly and the changes saved with the program.
a) Start up RSLogix and go on-line (this requires a Channel 1 connection such as a DH+
connection through the PCMK card). Double click on the channel configuration. Select
Channel 0 - System.
b) The Channel Configuration must be set up so that the modem will properly communicate with
the SLC-500. Make sure that the following parameters match those of the SLC 5/04 Channel
Configuration.
SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected]
TN612.DOC
PAGE 2
REV: OCT. 1998
SLC 5/04 Controller Channel Configuration - continued:
SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected]
TN612.DOC
PAGE 3
REV: OCT. 1998
SLC 5/04 Controller Channel Configuration - continued:
Sending Modem Setup Procedure:
Open the control panel in Windows 95 and double-click on the modem icon. This will bring up a dialog
box showing the modem properties. Make a note about which COM port the modem is set up on. If it is
COM1 or COM2, then record this. If it is COM3 or COM4, then the exact IRQ and memory address
must be obtained for the number shown and the address shown. Click on the OK button and then on the
General tab, press the “Properties” button. Make sure modem properties match those listed on the
following pages:
SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected]
TN612.DOC
PAGE 4
REV: OCT. 1998
SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected]
TN612.DOC
PAGE 5
REV: OCT. 1998
SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected]
TN612.DOC
PAGE 6
REV: OCT. 1998
RSLogix Driver Setup:
Under Configure Dialer just enter the phone number and when you communicate the Rockwell software
will automatically dial and make the phone connection.
SIXNET • Box 767 • Clifton Park, NY 12065 USA • +1 (518) 877-5173 • FAX +1 (518) 877-8346 • [email protected]
TN612.DOC
PAGE 7
REV: OCT. 1998