Specifications

Jumper Configurations
Table A-2
ZT 8832 Jumper Descriptions (continued).
JUMPER # DESCRIPTION
W16,
W17 J2 RS-485 Output Enable - selects the
method of enabling the RS-485 Transmit
Data and Request-To-Send drivers. With
W16 installed, the drivers are disabled.
With both W16 and W17 removed, the
drivers are always enabled. With W17
installed, the drivers are enabled with the
DTR bit of the serial port (I/O port address
3FCh, bit 0). Writing a logical 1 to DTR
enables the drivers and writing a logical 0
disables them. The power-on state of DTR
is a logical 0. See also W1-W6 (page A-3)
and W9-15 and W18 (page A-4).
W16 W17 Operation
† In Out Always disabled
Out In DTR control
Out Out Always enabled
W19 Watchdog Timer.
W19 Operation
In Enables watchdog timer
† Out Disables watchdog timer
†Factory default jumper configuration.
A-5