55xGenComm1_29
24
GenComm Page 0 - Communications Status Information
1. These are read only registers.
2. Registers 0 and 1 must both be read with a single message for them to be meaningful since
they are set after each message.
3. Registers 2 and 3 contain copies of the telemetry alarm flags of all satellites so that the
satellite that caused a dial out can be ascertained without reading the telemetry alarm flags
from all the satellites individually. This register is not latched, clearing the telemetry alarm flag
of a satellite will clear the corresponding bit in these registers when the hub updates them. The
hub will not assume that sending a system control message to a satellite to clear its telemetry
alarm flag will necessarily succeed, instead it builds registers 2 and 3 by reading the state of all
the satellites telemetry alarm flags periodically. Bit 1 represents satellite 1 etc.
4. Registers 4 and 5 contain communication error flags for all the satellites. A flag is set if, and
only if, the corresponding satellite socket is fitted, it is enabled by the corresponding ‘satellite
socket enable flag’ in page 1 - Communications Configuration, and the hub is not able to
communicate successfully with the satellite for any reason. Bit 1 corresponds to satellite 1 etc.
5. If any communication error flag changes from 0 to 1 the hub’s telemetry alarm flag will be set
and so cause a dial out if a modem is connected with dial out enabled, the satellites telemetry
alarm flag in register 2 or 3 will not be set since this would contradict its non-latching operation
as described in note 3 above. A system control function must be used to clear the hub’s
telemetry alarm flag before the connection is broken or the dial out will be repeated.
6. The meaning of the password status is shown in the table below.
7. If the password status is 0 (no valid password) then it is not possible to read the extended
exception information..
8. If the number of satellite sockets is 1-32 the unit is a hub, otherwise it is not. A hub with 8
sockets, for example, returns a value of 8 regardless of what is actually plugged into the
sockets or what the satellites state is, and will always respond to 8 consecutive slave
addresses starting with its own slave a1.
9. The GenComm version number allows a master to recognise the version of GenComm
supported by a slave device and act accordingly.
10. Registers 10 and 11 contain flags that indicate the available baud rates, bit 1 corresponds to
baud rate code 0 etc. If a bit is set the corresponding Baud rate is available.
11. The list of language codes that are available on a particular slave device can be obtained by
first reading the number of languages available and then reading that number of registers from
the beginning of the list of language codes available. Reading any further registers from the list
will return the unimplemented register value 0xFFFF. The order of the language codes in the
list has no significance and no assumptions should be made.
Registers
Register
offset
Name Min
value
Max
value
Scale
factor
Units Bits/
sign
0
Extended exception code
0
65535
16
1
Extended exception address
0
65535
16
2-3
Telemetry alarm flags for all
satellites
0 32
4-5
Communication error flags for all
satellites
0 32
6 Password
status
0
3
16
7
Number of satellite sockets
available
0 32
16
8
Number of languages available
for telemetry
0 128
16
9
GenComm version number
1
1
16
10-11
Baud rates available
0
32
12-127 Reserved
128-255
List of language codes available
0
65534
16
