User manual

A. Jumper Configurations
115
W28-31
RS-485 Transmitter Configuration - independently configures the transmitter input
source and transmitter enable for the RS-485 channels. The COM1 and COM2 serial
ports are software configured for RS-232 or RS-485 operation through System
Register 2. If configured for RS-485, the following jumpers adjust the RS-485
architecture to a specific application. These jumpers do not apply to the ZT 8903.
W28a W28b COM1 Transmit Enable
†
IN OUT COM1 DTR
OUT IN COM1 TXD (J1708)
OUT OUT Enabled
W29a W29b COM1 Transmit Input
†
IN OUT COM1 TXD
OUT IN Logical 0 (J1708)
W30a W30b COM2 Transmit Enable
†
IN OUT COM2 DTR
OUT IN COM2 TXD (J1708)
OUT OUT Enabled
W31a W31b COM2 Transmit Input
†
IN OUT COM2 TXD
OUT IN Logical 0 (J1708)
†
Factory default configuration for DOS systems.