User's Manual

78
SERIES II INTELLIGENT DATA/FAX MODEMS
When two Series II Modems are connected in Normal mode (not using
error correction), Xon/Xoff can be used to control the flow of data
between the modems. Flow Control can be turned on or off with the
Normal Mode Modem Flow Control commands. When the modems
are connected in Reliable mode, a different method of modem Flow
Control is used, and the commands for Normal Mode Modem Flow
Control are ignored.
When you are using Speed Conversion in Normal Mode, you must
activate the modem’s Normal Mode Modem Flow Control. (Speed
Conversion is explained in Section 5.4.11.)
Send Xon/Xoff Characters #X
The #X phone interface command allows the Series II Modem to send
either a single or multiple Xoff characters at the modem's buffer full
level. When the Modem's buffer reaches it's "buffer full" level, the next
character received causes another Xoff to be sent for every character
subsequently received by the Modem.
The AT#X0 command (factory default setting) causes one Xoff to be
sent until the buffer reaches the Xon level. The AT#X1 command
causes an Xoff to be sent for every character received after the modem
reaches its buffer full level.
Hewlett-Packard ENQ/ACK Pacing &E9
If the Series II Modem is being used with Hewlett Packard (or similar)
equipment that employs ENQ/ACK pacing, the modem can be
configured to respond to ENQ/ACK commands, making it compatible
with HP systems. Doing so does not affect any other flow control or
pacing already configured in the modem.
When configured for ENQ/ACK, the ENQ (Control-E) and ACK
(Control-F) signals from the HP equipment will be accepted and re-
sponded to according to Hewlett-Packard protocol.
Normal Mode Modem Flow Control On &E11
When two Series II Modems are connected in Normal mode (not using
error correction), Xon/Xoff can be used to control the flow of data
between the modems. Flow Control can be turned on or off with the
Normal Mode Modem Flow Control commands. When the modems are