Purchase now: Allen Bradley 1747-CH0RAD Remote Access Modem Kit
Purchase now: Atlantechdrives provides you the 1747-CH0RAD, a highly specialized Remote Access Modem Kit engineered by Allen Bradley for the SLC 500 automation family. Before the widespread adoption of secure VPNs and plant-wide Ethernet/IP networks, providing remote technical support to a factory located hundreds of miles away was a massive logistical challenge. The 1747-CH0RAD bridges this gap by providing a complete industrial-grade serial modem solution designed specifically to connect to the RS-232 «Channel 0» port of SLC 5/03, 5/04, and 5/05 processors. By wiring this modem to a standard analog telephone line, an automation engineer can dial into the PLC from their office, utilizing RSLogix 500 to perform online code edits, troubleshoot machine faults, and extract historical production data as if they were standing directly in front of the control cabinet.
Technical Specifications of the 1747-CH0RAD
The 1747-CH0RAD kit includes a robust industrial modem, the necessary DB-9 serial interface cables, and configuration media. It utilizes the DF1 communication protocol, which is native to the Allen Bradley Channel 0 serial architecture.
- Part Number: 1747-CH0RAD
- Kit Type: Industrial PLC Remote Access Modem Kit
- Compatible Processors: SLC 5/03 (L53x), SLC 5/04 (L54x), SLC 5/05 (L55x)
- PLC Interface: Channel 0 RS-232 (9-pin D-Sub)
- Communication Protocol: DF1 Full-Duplex or Half-Duplex
- External Connection: Standard analog telephone line (POTS)
- Primary Function: Remote tele-diagnostics and SCADA data polling
Expert Tips: DF1 Protocol and Modem Initialization
Connecting a modem to a PLC requires strict adherence to serial communication parameters. Expert Tip: Out of the box, the SLC processor’s Channel 0 port is typically set to DF1 Full-Duplex. To successfully integrate the 1747-CH0RAD, you must configure the Channel 0 settings in RSLogix 500 to properly handle modem handshaking. You will likely need to configure «Modem Init Strings» (AT commands) within the PLC port setup. These commands tell the modem to auto-answer incoming calls from your engineering laptop. Furthermore, ensure the port baud rate, parity, and stop bits in your PLC hardware configuration perfectly match the physical capabilities of the modem, or the serial link will fail to establish.
Installation Advice: Surge Protection and Grounding
Industrial telephone lines are notorious for carrying severe electrical transients, especially during lightning storms. When installing the 1747-CH0RAD inside your control cabinet, it is absolutely critical to pass the incoming analog telephone line through a DIN-rail mounted surge suppressor before connecting it to the modem. If a lightning strike hits the external telecom infrastructure, the voltage spike will travel directly through the modem and into the Channel 0 port of your SLC processor, instantly destroying the CPU. Proper grounding of the modem and shielding of the RS-232 serial cable will ensure decades of reliable remote access.
Frequently Asked Questions (FAQs)
Q: Will the 1747-CH0RAD work with an SLC 5/01 or 5/02 processor?
A: No. The SLC 5/01 and 5/02 processors do not possess a 9-pin RS-232 Channel 0 port; they only have an RJ45 DH-485 port. This modem kit requires a true RS-232 serial connection.
Q: Can I use this modem for high-speed SCADA polling?
A: While the 1747-CH0RAD is excellent for remote programming and diagnostics, dial-up serial modems have inherent bandwidth limitations (typically 33.6 kbps to 56 kbps). It can be used for SCADA data polling, but the update rates will be significantly slower than a modern Ethernet connection.
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For radio-frequency industrial communications, this module is technically compatible with the 1747-KE communication interface.
