User guide
ASCOM USER GUIDE
High Speed Base Band Modems
51
8.1 X21 (V.11)
8.1.1 15 Way D-type X.21 (V.11) Connector pin allocation.
8.1.2 Module Link Settings
J1 - X.21 T (Transmit data) Circuit Termination
This link connects a 120 ohm load resistor across the T circuit in position 1-3. This helps
maintain signal rise times and minimises reflections at rates greater than 9.6 kbps over long
lines. At lower rates and over short lines the termination resistor may be omitted, (link set
position 1-2).
3
1
2
3
1
2
J1
J2
Interface Module -
Top View
Pin Type SITS
A-wire B-wire Unbal Circuit Description 89/43
8 G Signal Ground / Common Return Common
15 1 S EXT External Signal Element Timing Load
2 9 T Transmit Load
4 11 R Receive Generator
3 10 C Control Load
5 12 I Indication Generator
6 13 S Signal Element Timing Generator
7 14 B Byte Timing Generator
8 USER INTERFACES
8
50 ASCOM USER GUIDE
High Speed Base Band Modems
7.7 CHANGING PASSWORDS
Only when logged in at Supervisor level is it possible to see and modify the user passwords. To
change a password, use the UP or DOWN ARROWs or TAB to move the cursor to the required
password and then enter edit mode by pressing the SPACE key. Edit the password as required
(the easiest way to do this is deleting the existing line by pressing CTRL-C and then typing the
new value). Press ENTER to complete the task. You will note that the “Save Settings required”
message appears on the screen – ensure that you do this by clicking on the programme key
on either the Configuration or Options pages.
To enable user level access without a password, un-check the “Use Password” box.
The system is programmed to automatically logout when the DCD pin goes OFF. Un-check the
“DCD Logout” box to prevent this.
You can also change the length of the inactivity timeout for logging out when the terminal is
not used. This is changed using edit mode in the same way as changing passwords.
AM64/1024A V3.0
Password
Status: No Alarm
Guest= Helen
User= Jennifer
Techie= Michael
Supervisor= Helmut
[x] Use Password [x] DCD Logout
Auto-logout (mins)= 20
Logged in as Supervisor
Logout