"I have been unsuccessfully attempting to use the RS-232 serial interface of my Endevco® model 6634C vibration amplifier, using National Instruments (NI) LabView and their I/O card. What might I be overlooking?"
First, regardless of I/O card or software selection, the optional RS-232 serial interface board (#35843) for the model 6634C must be properly installed, in order for it to work. Once successfully integrated, the front panel of the vibration amplifier can be remotely controlled via this interface. A detailed instruction guide to software communication protocol and command syntax may be found within Section 4 of the product manual. As the serial interface of model 6634C is used solely for front panel remote control, it does not support data transfer functions.
In order for the RS-232 serial interface to properly operate, the serial interface cable must be properly wired, and an adaptor assembly constructed. Here's a quick "How To" guide for wiring and adaptor assembly:
Figure 1, below, is a diagram representative of the pin out connection. Please note that gender call-outs refer to the contact pins themselves. The RS-232 adaptor assembly uses a standard 9-pin DB9 RS-232 connector, with the male type on one end and female type on the other.
Figure 1: Endevco model 6634C vibration amplifier pin-out connection diagram. The bill of materials for the required adaptor assembly may be found below:
It is necessary to solder wires to the DB9 connectors, as diagrammed above in Figure 1. When soldering, please keep in mind that total length of the adapter is not critical.
Typically, 4" to 10" will work just fine. For visual reference, a partially assembled soldered connection is shown in Figure 2:
While National Instruments LabView has been identified within this customer example, it is important to note that the proposed fix is not strictly confined to LabView. It will work on any host, so long as the communication protocol and command syntax is properly followed, as defined within the supplied product instruction manual.