Ibm 7852-400 Dip Switch Settings; Xon/Xoff Modems; Ring Detection - IBM 265 Service Manual

v condin
v ripo
4. Save the changes.

IBM 7852-400 DIP Switch Settings

If you are using a 7852-400 modem to enable service processor communications, for
proper operation, the dual inline package (DIP) switches must be set according to the
following table:
Switch
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
* Only switches 11 and 12 are changed from the factory default settings.

Xon/Xoff Modems

Some early modems assume software flow control (Xon/Xoff) between the computer
and the modem. Modems with this design send extra characters during and after the
transmitted data. The service processor cannot accept these extra characters. If your
configuration includes such a modem, your functional results may be unpredictable.
The sample modem configuration files included in this appendix do not support these
modems, so custom configuration files are necessary. Anchor Automation 2400E is an
example of such a modem.
If you experience unexplainable performance problems that may be due to Xon/Xoff
characters, it is recommended that you upgrade your modem.

Ring Detection

Most modems produce an interrupt request each time they detect a ring signal. Some
modems generate an interrupt only on the first ring signal that they receive. AT&T
DataPort 2001 is an example of such a modem.
Position Function
Up Force DTR
Up Flow Control &E4
Down Result Codes Enabled
Down Modem Emulation Disabled
Up Auto Answer Enabled
Up Maximum Throughput Enabled
Up RTS Normal Functions
Down Enable Command Mode
Down Remote Digital Loopback Test Enabled
Up Dial-Up Line Enabled
*Up AT Responses Enabled (Extended Responses Disabled)
*Down Asynchronous Operation
Up 28.8KB Line Speed
Up
Up CD and DSR Normal Functions
Up 2-Wire Leased Line Enabled
Appendix D. Modem Configurations
317