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RS-232 Communications
RS-232 Peripheral Equipment Requirements
Any peripheral equipment connected to an RS-232 serial port must meet the following criteria:
1. Peripheral equipment must be UL listed.
2. The equipment must have an EIA standard RS-232C or RS-232D communications protocol.
3. The equipment must NOT be installed over or in a hazardous location.
RS-232 Connections
TO A DEVICE LESS THAN 50 FEET FROM THE CONSOLE
Veeder-Root recommends that you use a null-modem cable no longer than 50 feet (15 m) for direct connections between
the console and a remote device. Cable runs longer than 50 feet can result in data errors, component damage, or both.
TO A DEVICE MORE THAN 50 FEET FROM THE CONSOLE
If cable runs longer than 50 feet are needed, two short-haul modems should be used, one at the console and one at the
remote device. We recommend an asynchronous short-haul modem, Black Box model ME800A, or equivalent at the
console and at the remote device. For more information, you can contact Black Box at - phone: 1-724-746-5500, fax: 1-
724-746-0746, or at their Internet address
http://www.blackbox.com
Figure 15 illustrates how to connect two short-haul modems between the console RS-232 Interface Module’s or
Auxiliary RS-232 Interface Module’s DB-25 connector and the remote device.
Connections to telephone lines must meet the following criteria:
•
Connection to telephone equipment is subject to local regulations.
•
Maximum short circuit current: 0 amperes.
•
Maximum open circuit voltage: 0 volts.
