Quatech SSP-200, SSP-300 user manual

Selection of half duplex mode operation is dependent upon the configuration software and/or the operating system used. Each of these, however, ultimately control the half duplex mode by accessing the PCMCIA Configuration Register on the SSP-200/300.

CAUTION:

When operating in half duplex mode, the transmitter output drivers must be disabled before receiving any information. Failure to do so will result in two output drivers being connected together which may cause damage to the adapter, the computer, and/or the peripheral equipment.

6-4 SSP-200/300 (Rev. I and later) User's Manual