Black Box IC107A-R3 - Manual (Page 10)

9
CHAPTER 3: Configuration
5. Normally, the Converter’s frame ground is isolated from its RS-232 signal
ground. But if you want to connect frame ground to signal ground, you’ll
need to solder a 100-ohm, 500-mW resistor to the terminals of location W7.
(You could also use a wire jumper, but you’d need to make sure that any
ground-loop currents caused by voltage-potential differences between the
RS-232 and RS-422/485 sides are limited to acceptable levels—a strong
ground loop could damage the Converter and attached equipment.)
CAUTION!
Any soldering should be done only by qualified, experienced personnel.
6. If your Converter is a standalone IC107A-R3 or IC107AE-R3 model: Put the top of
the Converter’s case back on and secure it in place by screwing the bottom
screw back in.
Figure 3-1. The Converter’s circuit board.
Board component plugs
into RS-422/485 connector
RS-232 Connector