ACC HDLC-NRM (SDLC) User's Guide

Protocol Specific Configuration
Protocol Configuration Values
Chapter 4 55
HDX - Half Duplex
This option is only applicable for the primary stations. The setting of this
option for a primary terminal will prevent the transmission of frames to
ANY SECONDARY TERMINAL while the poll is outstanding to a
terminal configured as half duplex.
If the half duplex option flag for a primary terminal is zero (0), then the
terminal will operate in full duplex mode.
RPC - Remote Power Control (Extension feature)
Set to invoke support for the remote power control feature for the
station. Stations do not support remote power control by default. This
procedure is outside of the standard procedure for HDLC-NRM (SDLC),
as defined in ISO 4335.
This option is only applicable for primary stations. Secondary stations
will respond as expected to the RPC sequence if received, without setting
this configuration option.
The RPC command is defined as a UI command frame, with empty I-field
and P bit equal to “1”. The RPC procedure operates outside of the normal
mode setting procedure using the SNRM command.
When the RPC is enabled, the primary station will initiate the RPC
command for a station when the terminal is enabled. The primary
station will continue to send the RPC command until either a DM or
FRMR response is received. The primary station will then proceed to set
the mode using the SNRM command.
TWS - Two Way Simultaneous
Set to enable two way simultaneous operation of a station. This option
is only configurable for primary stations. Primary stations operate in two
way alternate mode if this option is set to zero (0). Secondary stations
will operate in TWS if permitted by the discipline enforced by the
corresponding primary station.
The setting of the TWS option will allow frames to be sent to the
secondary station while the poll is outstanding to that station.