RS232 Communication
RS232 Communication
RS232 control is not necessary for operation, but it is a convenient way to control displays from a computer at a distance. If your installation will not use RS232 control, skip this section.
Everything you can do with the remote, you can do with RS232 commands. Plus, you can send inquiries to the displays and find out the current settings and values.
RS232 connections are made with cables like Ethernet straight-through cables.
You need an adapter to go from the computer’s 9-pin serial output connector to an RJ-45 connector. Adapters of this type are readily available at computer and electronic supply stores. You will only need one adapter. The adapter is not pre- wired. You will make three connections inside the adapter, as described below.
Note: It is important that the RJ-45 cable has “straight through” connections. To see if your cable is correct, hold the two connectors side by side with the ends pointing in the same direction. Look at the sides of the connectors that do not have the locking tab. If the colors of the wires inside the connectors are the same left to right for both connectors, this is the correct cable. If the colors are mirror reflections of each other, it is the wrong type.
Wiring the adapter
To go from 9-pin D-sub serial connector on the back of the computer to an RJ45 connector, use a standard RJ45-to-9-pin adapter. Wire it internally as shown. The wiring shown for this adapter is correct for straight-throughcables. Straight-through cables are wired 1-to-1, 2-to-2, etc.
| RJ45 | 9-pin |
| | |
Yellow wire | 6 | 3 |
| | |
Black wire | 3 | 2 |
| | |
Green wire | 5 | 5 |
| | |
18
5 4 3 2 1
9 8 7 6
RJ45 looking into the socket
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