IBM 3174 - Page 180

Modem Specifications and Setup
I IBM 5841, 5842, and 5853 Setup
IBM 5841, 5842, and 5853 modems are operated inAttention Command Set (AT) mode. Any parameters set
bycommands that are required for operation withthe AEA feature are the same as for Hayes modems.
However, the switchsettings for IBM modems are not compatible with Hayes,and must be set as specified
here.
The six front panel switches must be in the Out position. Inaddition, the eight configuration switches must
be set as described in Table B-1 or Table B-2 on page B-4.
Table B-1 . IBM584x Modem Switch Settings
Switch
Number
Option
Name
Switch
Setting
Description
1
Receive Line Signal
Detect (RLSD). (Also
known as Carrier
Detect [CD] or Data
Carrier Detect [DCD])
On
Carrier Detect is raised at connection time.
2
Reset to Default
Options on Loss of
Data Terminal Ready
(DTR)
Off
When this switch is set to OFF, the 3174 can reset the
modem to a known state by dropping DTR. If register
settings are not required for special installation
requirements, this reset can be used to avoid unexpected
results that can arise from previous use. Not used on
5841.
3
Transmit Timing
Option (Synchronous
mode only)
Not
relevant
4
Asynchronous or
Synchronous Mode
On
Asynchronous mode is used.
5
Source of Data
Terminal Ready (DTR)
On
AEA controls DTR.
6
Transmit Clocking from
Remote Modem
(Synchronous mode
only)
Not
relevant
7
Request to Send (RTS)
Off AEA controls RTS.
8
Data Set Ready (DSR)
Off (5842)
On (5841)
DSR is raised at connection (5842).
DSR is always on (5841).
Appendix B. Using a Modem andan ASCII Terminal With the 3174 Asynchronous Emulation Adapter B-3