BIT SWITCHES
A256/A257 2-4 SM
Bit Switch 09
No. FUNCTION COMMENTS
0
Not used Do not change the factory setting.
1
New session within the
same call
0:
Not accepted
1:
Accepted
0:
If a new R:CSS is received, the machine sends
back S:RSSN.
1:
If a new R:CSS is received, the machine sends
back S:RSSP. Set this bit to 1 for German PTT
approval tests.
2-7
Not used Do not change the factory settings.
Bit switches 0A to 0F are not used.
Bit Switch 10 (Dch. Layer 1)
No. FUNCTION COMMENTS
0
Connection detector
0:
Disabled
1:
Enabled
In most countries (including Europe), this should
be disabled.
1
2
Layer 1 T3 timer
Bit21Time
00 5 s
0 1 29 s
1 0 10 s
11Not used
This should be kept at 5 s (both bits at 0) for
normal operation. However, you may have to
change this during PTT approval tests.
3
Layer 1 T4 timer
0:
Not used
1:
Used
Set this bit to 1 for French PTT approval tests.
4-5
Not used Do not change the factory settings.
6
INFO1 signal resend
0:
Resend
1:
No resend
0:
If there is accidental noise in the INFO1 signal,
some DSUs may not reply to the INFO1 signal
with INFO2. Try changing this bit to 0, to resend
INFO1 before the machine displays “CHECK
INTERFACE”.
7
Loop back 4 mode
0:
Disabled
1:
Enabled
This is normally kept at 0. However, set it to 1 for
British PTT approval tests.
Bit Switch 11 (Dch. Layer 2)
No. FUNCTION COMMENTS
0
Not used Do not change the factory setting.
1
Type of TEI used
0:
Dynamic TEI
1:
Static TEI
This is normally fixed at 0. However, some
networks may require this bit to be set at 1 (see
below). In this case, you may have to change the
values of bits 2 to 7.
2
to
7
Static TEI value Store the lowest bit of the TEI at bit 7 and the
highest bit of the TEI at bit 2.
Example:
If the static TEI is 011000, set bits 3
and 4 to 1 and bits 2, 5, 6, and 7 to 0.