B&B Electronics GW-7552 - Manual - Manual (Page 12)

GW-7552 PROFIBUS/MODBUS GATEWAY User Manual (Version 1.40, Apr/2012) PAGE: 12
Table 6 Jumper position for the RS-485 port
Pull high/low resistor Condition
Enabled
(default)
− The GW-7552 is the master in RS-
485 bus or
− the number of devices connected
to the RS-485 bus is less than 10
Disabled − The GW-7552 is a slave in RS-485
bus or
− the number of devices connected
to the RS-485 bus exceeds 10
Figure 9 Configuration of pull high/low resistor for the RS-485 port
2.3.4 PROFIBUS Connection
The PROFIBUS interface of the GW-7552 is a DB9 female connector. The
connector uses the standard Profibus 9 pin assignment. It is recommended to
use a standard PROFIBUS cable and connector (DB9 male). As with every
serial bus the rate of safe data transmission in a Profibus network decreases with
increasing distance between master and slave. Table 7 shows the transmission