Switch package SW3 is used to select the ET baud rate for communications. The ET baud rate must be the same
as the communications baud rate selected on the BMUX CPU board (see Figure 1). Set SW3 using Table I.
Note: Switch position 4 on SW3 is UNUSED.
TABLE I
C = CLOSED
0 = OPEN
Example: If the communications baud rate is 4800, CLOSE switches
1,2, and 3 on SW3.
The switches on switch package SW4 specify the ET’s address as follows:
SWITCH
BINARY WEIGHT
1
2
4
8
16
32
Note: SW4-7 and SW4-8 are UNUSED.
Remember: The ET’s address is one less than the transponder number. Add the BINARY WEIGHT of the OPEN
switches to obtain the ET’s address. For example:
ET #35 would have an address of 34. So, switches 2 and 6 would be OPEN.
ET #47 would have an address of 46. So, switches 2,3,4, and 6 would be OPEN.
The ET has a special communications feature. It can either:
l
Communicate using the “standard” DC communications channel.
OR
l
Use its RS232C port to tie directly into a modem.
Note: The ET’s RS232C port is used ONLY to tie into a modem for communications over a leased telephone line.
The ET CANNOT COMMUNICATE DIRECTLY WITH THE BMUX OVER THIS PORT.
For standard communications, jumper wires JWl, JW2, and JW3 are IN. When the RS232C port is being used,
these jumper wires must be removed.
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