55xGenComm1_29
27
10. If a password is changed to 0000 then it will be disabled. The password status will then default
to the highest level that is disabled rather than 0 when an invalid password is entered, the
password times out or the link to the master is lost. Any attempt to write a password of 0000 to
register 32 and 33 will be treated exactly as if an invalid password was entered.
11. A hub is intended to provide security for all its satellites using its own passwords, thus avoiding
the complexity of managing passwords in every satellite separately. To facilitate this each
satellite must have all its passwords disabled by setting them to 0000. If this is not done it is not
possible to enter a password into a satellite unless the write password is entered into the hub
first. This is necessary to simplify the message filtering mechanism needed in the hub but is not
a problem if the hub is used to provide security to the satellites as intended.
Registers
These are a mixture of read/write (R/W) and write only (W) registers.
Register
offset
Name Min
value
Max
value
Scale
factor
Units Bits/
sign
R/W
0
Current slave ID
1
247
16
R/W
1
Site identity code
0
65534
16
R/W
2
Device identity code
0
65534
16
R/W
3 Baud
rate
0
12
16
R/W
4
Current language code
0
65534
16
R/W
5 Unimplemented 0xFFFF
0xFFFF
16
6-7
Satellite socket enable
flags
0 32
R/W
8
Master inactivity time-
out, 0 means never time-
out
0 36,000
0.1
Secs
16
R/W
9
Password time-out, 0
means never time-out
0 36,000
0.1
Secs
16
R/W
10-31 Reserved
32 Current
password 0 9999
1
16
W
33
Compliment of current
password
55536 65535 1
16
W
34 Reserved
35 Reserved
36 Reserved
37 Reserved
38
Set new Write password
0
9999
1
16
W
39
Compliment of new
Write password
55536 65535 1
16
W
40-255 Reserved
