Digi TransPort WR31 User Manual page 544

Configure legacy protocols
Retransmit APACS 30 string if error detected
Enabling this setting causes the router to retransmit the APACS 30 string to the terminal if an
error is detected, such as no ACK received from terminal.
STX/ETX removal
Enabling Del STX&ETX causes the router to strip off the STX and ETX characters that normally
surround the APACS 30 string before sending it to the host. Enabling Del STX only causes the
router to strip the STX character only.
Do not transmit ENQ characters
The TPAD protocol normally uses the ENQ character to indicate that a call has connected and
that the TPAD terminal may proceed with the transaction. Enabling this parameter prevents the
router from transmitting ENQ characters to the TPAD terminal when a connection is made.
Delay sending ENQ characters to TPAD terminal for x milliseconds when a call has been
connected
Set s the delay, in milliseconds, from when the router first connects the call to when it transmits
the ENQ to the terminal. By default, there is no delay.
Wait for x milliseconds for an ACK before retransmitting the data
The time the router waits for an ACK character to be received after sending data to the terminal.
If an ACK character is not received within this time, the data is retransmitted. A value of 0 sets a
delay of 1 second (the default).
Transmit TPAD transactions directly in a Synchronous frame
If enabled, TPAD transactions are transmitted without any outer protocol, such as X.25, such as
they are placed directly in a synchronous frame on ISDN. This sometimes referred to as HDLC by
certain card acquirers.
Include LRC
The LRC (Longitudinal Redundancy Check) is a form of error checking that may be required by
some TPAD terminals. When the Include LRC option is enabled the router will check the LRC sent
by the terminal and if it indicates a problem has occurred NAK the message. If this parameter is
enabled but no LRC is sent by the terminal, the transaction is not forwarded to the host.
Include LRC line
This parameter is normally disabled so that any LRCs received from a TPAD terminal will be
removed before the transaction data is transmitted to the remote host. In most cases this is
acceptable because the network will provide error correction and so the LRC is redundant. In
some circumstances it may be necessary to enable this parameter so that the router transmits
the LRC to the remote host along with the transaction data.
Force parity when sending data to the terminal
If enabled, the router always uses even parity when relaying data from a remote host to a locally
connected TPAD terminal. To allow data to pass through without the parity being changed,
disable this setting.
Digi TransPort WR Routers User Guide
Configure TPAD parameters
544