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By either swapping the value of the address in the command block, or by
swapping the value at the directory address before making a dial request; a
huge directory of telephone numbers becomes available, limited only by the
amount of free data registers within the PLC.
3.5.6 Setting fixed messages in the modem
Fixed (text) messages are stored within the modem, so must be pre-set by connecting
the modem to a PC terminal, and using the command:
Where n = the message address in the range 1 to 9
<message> may be up to 48 characters long.
Example: AT%MSG2=Pumping Station No. 2 [stores message in address2]
b15
D(x+2)
Msg. #1
Where (x+2) = Command Block address +2
1-9h
for Fixed Message addresses
A-Dh for WAT Messages/Data addresses (see section 3.6 for more information)
Eh for On-Line polling
Fh for Stay On-Line
0h for end of messages, hang up
Message addresses are stored in HEX and must include all 4 numbers, e.g. 12F0 not
12F. [send 2 messages from addresses 1 and 2, then Stay On-Line (F)]
When a value of 1 to 9 is found in the returned data, the corresponding message is
looked up then sent to the remote site.
The modem will automatically hang up when a value of 0 (zero) is found or after all
four messages have been actioned.
When the hexadecimal value E is found; the modem stops processing messages, sets
the Transmission Complete bit in the PLC command register, then resumes polling.
However, the modem does not hang-up, terminating the call. This feature is useful
when more than four transactions are required, and is particularly useful when doing
Wide Area Telemetry.
When the hexadecimal value F is found; the modem stops processing messages, sets
the transmission complete flag, but does not resume polling. Again the modem does
not hang-up, terminating the call. This feature is useful when an error has occurred
that requires operator intervention from a remote site.
Example 3-7 Setting Messages from the PLC
AT%MSGn = <message>
Msg. #2
Msg. #3
MOVP H12F0 D1002
MOVP HABE0 D1002
20
b0
Msg. #4
Message register
Set Fixed messages 1,2 and
Stay on-line.
Set WAT A,B then On-line
monitoring.
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