User`s manual

30 www.rabbit.com RabbitFLEX BL300F Options
4.3.3 RS-485
You can select an RS-485 communications channel with or without termination or jumpered termination
for the most flexibility. The header J8, between J6 and the RS-485/RabbitNet port, is the header for RS-
485 jumpered termination. J8 pin numbers are marked in Figure 4-8.
Figure 4-8 Location of J8 for RS-485 Jumper Termination
See Table 4-4 to determine jumper setting for enabling/disabling termination.
For more information on termination see Section 5.2.
The RS-485 lines come out on connector J6 (see Figure 4-2). Signal A is pin 8 (485+) and signal B is pin 7
(485-). The RS-485 protocol is a packet driver implemented by the library packet.lib, which can be
found in the folder named “lib” where you installed Dynamic C.
Table 4-4. Jumper Settings for RS-485 Termination
Termination Status Jumpered Pins
Enabled 1 - 2 and 5 - 6
Disabled No jumpers