3Com 3C13618 Command Reference Manual page 107

Parameter
AnswerTime time: Duration of answer tone. It ranges from 500 to 2000 milliseconds,
and the default is 500 milliseconds.
TradeTime time: Time for trading. It ranges from 30000 to 12000000 milliseconds,
and the default is 60000 milliseconds.
PacketInterval time: Time for packet interval. It ranges from 3500 to 10000
milliseconds, and the default is 5000 milliseconds.
Description
Using the pos-server fcm command, you can configure the FCM card parameter in
the MODEM negotiation process. Using the undo pos-server fcm command, you
can restore the default value,
In POS access application, the MODEM on the FCM card is normally taken as the
answer port, while the MODEM built in the POS terminal is calling party. The basic
MODEM communication process is that the POS terminal makes a call, when
detecting signals the answer party will answer and send answer tone to the POS
terminal, and when the POS terminal receives the answer tone the two parties will
begin MODEM negotiation Due the to complicated phone network and various levels
of signal quality and delay, for the network system with poor quality, too short answer
time setting will cause the failure of MODEM negotiation, and you can only find Up
and Down at the MODEM interface of the router, without data packet sending and
dispatching. Now you can increase the time value of the AnswerTime.
Communication begins when negotiation is completed. As POS terminal adopts SDLC
protocol, the monitor frame and data frame needs timeout and repetition mechanism
to deal with exception communication. The parameter PACKET INTERVAL is used to
set the time value of timeout. You need to increase the value for the system with
jumbo packet (more than 512 bites) communication.
Because the convergence rate of POS network is normally high, in order to improve
the utilization efficiency of the access port, it is necessary to prevent a POS terminal
from occupying resources within a long time after dialing in. So you need to manage
the time of one single trade. And the parameter TradeTime can realize the function. If
it exceeds the set longest trade time when a POS terminal dials in, the router will
hook up initiatively to unlock the deadlock.
Normally the default parameters can satisfy application. But when exception
communication occurs, the parameters need to be modified according to the above
description.
For related commands, see pos-server enable.
System Management
91