User`s manual

Installation
15 User’s Manual - DSP19.2 Fast Poll Modem
S1-1, S1-2, S1-3 − Modem Data Rate
y S1-1, S1-2, S1-3: Select the modem speed per Table 2-2
Table 2-2. Modem Operating Speed
To Select… Set Switch S1-1 to… Set Switch S1-2 to… Set Switch S1-3 to…
19,200 bps OFF OFF OFF
9600 bps ON OFF OFF
2400 bps OFF ON OFF
Bell 202T OFF OFF ON
V.23/1200 ON ON ON
For modem speeds of 2400 bps or higher, the modem uses QAM modulation automatically.
When the modem is operating at 1200 bps either in Bell202T or ITU-V.23 mode, the modem
uses FSK modulation.
S1-4 − Async Character (Fast-Poll Mode Only)
y S1-4 ON = 11 bits
y S1-4 OFF = 10 bits (default)
Switch S1-4 selects whether the async character is 10 or 11 bits long. This switch setting is
ignored when the modem uses FSK modulation.
S1-5 − Auto RTS
y S1-5 ON = Enable Auto RTS
y S1-5 OFF = Disable Auto RTS (default)
For data terminals that do not provide hardware Request To Send (RTS), set switch S1-5 to
ON to enable auto RTS mode. In this mode, TXD is detected at the modem and an internal
RTS signal is turned ON. After training completes, the TXD is transmitted to the remote
modem. The transmitter turns itself off if no TXD is detected after a pre-determined length of
idle time.
S1-6 − Transmit Carrier Control
y S1-6 ON = Constant carrier
y S1-6 OFF = Controlled by RTS (default)
Switch S1-6 selects either constant or switched carrier. Constant carrier allows DTEs, such
as asynchronous terminals or RTUs, to operate with modems, without requiring an input