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HP 27130B
BREAK DETECTION
The firmware notifies the host of receiving a break from the device by sending an unsolicited event
status, if enabled.
HANDSHAKE TIMER
After sending an ENQ, the firmware will wait up to the specified timeout for the ACK. If the ACK is
not received within the given time and if the ENQ retry is enabled, an ENQ will again be sent. This
will continue until an ACK is received. The default value is five seconds. The clock resolution is one
second. The timer can be programmed from 1 to 255 seconds by using the WCC, SF 18. A zero value
will defeat the timer; that is, there will be no timeout.
If enabled, a handshake timeout will generate a IIhandshake timed out" event.
ADDITIONAL OPTIONS
Six additional options are available for special use, as follows:
1. Do not terminate the text record on errors
2. Quoting character mode
3. Conditional output separators appendage
4. Signal (interrupt) characters
5. Implicit device X -ON
6. Insert a null character into the receive buffer when a break is detected.
All six options are configured by using Write Card Configuration, Subfunction 31 (WCe, SF 31).
Error Handling
Under normal MUX firmware operation, the incoming text is terminated when any receive data error
is encountered. Furthermore, the character causing the error is added to the text record for the host.
This allows the host to detect the undesirable error condition.
If the Do Not Terminate Text Record On Error option is enabled, the firmware will not terminate the
text record. The incoming character with the error will be replaced by the user-specified replacement
character which has a default value of 7FH
("DELII).
The replacement character will be added to the
text buffer and will be echoed, if echoing is enabled. The buffer, however, will be marked "bad" when
eventually terminated and sent to the host.
Under normal operation, the incoming text is terminated when any error is encountered.
Furthermore, the character causing the error is added to the text record for the host. This allows the
host to detect
un~irable
error conditions.
If the "00 Not Terminate Text Record On Error" option is enabled, the MUX firmware will not
terminate the text record. The incoming character with the error will be replaced by the
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