Zca (Zero Called Address) 7 - AT&T 7500 User Manual

CHAPTER 4: DEFINITIONS OF 7500 OPTIONS
Select eia, if you want the 7500 to use the Clear-to-Send (CTS) lead to indicate whether it is ready
to receive data from your data terminal. When it is not ready to receive data from your terminal, the
7500 turns off CTS. When it is ready to receive data, it turns on CTS.
When you select off, the 7500 cannot control the flow of data from your data terminal.
Without Help
*For a Mode 2 call, this option is in effect only at the high-speed endpoint (see Match.speed).
ZCA (Zero Called Address)
Configurations: Asynchronous DTE
This option is used exclusively with 5ESS switch DX.25 modem pooling feature.
When the 7500 initiates a data call, with this option on, it uses a called address consisting of 10
zeroes.
The 5ESS switch modem pooling feature uses a special telephone number consisting of 10 zeroes
when it is setting up the call from the 7500 to the network. The network automatically routes the call
to the appropriate data endpoint. This special telephone number is called the "Zero Called Address."
The capability for using Zero Called Address is controlled through option setting on the front panel of
the 7500. Set ZCA to on only if you are installing a 5ESS modem pool.
Without Help
70
Asynchronous DCE and Asynchronous DTE
Option Values For Trans.flow
Front Panel
With Help
OFF
0
XON
1
2 EIA
Asynchronous DTE
Option Values For Zero Called Address
Front Panel
With Help
0 OFF
1
ON
CMD Factory Value
Mode
DCE DTE
X
off
xon/xoff X
eia
CMD Factory Value
Mode
DTE
X