USER'S GUIDE ____________________________________________________________________
52 ___________________________________________________________________ M211187EN-C
Modem DXL421 (Optional)
The DXL421 modem is a leased line modem module compliant with
V.21, 300/300 bps FSK, V.22 1200/1200 DPSK, and V.23 1200/1200
bps FSK. It is applicable to long distance communications (~10 km)
using a leased telephone grade cable. It should not be used in public
telephone networks because that requires certain approvals by the service
provider. However, most of the commercial modems that comply with
the CCITT standards, as well as the DMX50 and DMX55 modems for
the Vaisala MILOS 500, can be used with the DXL421 modem.
If the modem is installed (the unit was ordered with the modem option),
connect the incoming signal wires to the DLX421 modem line screw
terminals 3 and 4 . See Figure 29 below.
NOTE
The DXL421 modem replaces the DMX501 modem. The DMX501
modem is no longer available but it can still be used with FS11.
The replacement of the modem does not cause any changes to the data
transmission through modem, except that v.22 bis is no longer supported.
The FS11 serial commands for configuring the modem settings work
only for the DMX501 modem.
NOTE
The cable shield of the modem cable must be properly grounded in the
cable gland of the interface unit's enclosure; see Figure 25on page 48.
1303-065
Figure 29
DXL421 Modem Wiring
If the DXL421 modem is not installed, it can also be retrofitted to the
FSI102 interface unit. To do this turn the AC (mains) power switch (also
the battery backup switch if installed) off.
