Aalborg SDPROCs - Manual (Page 41)

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The protocol described below allows for communications with the unit using either a
custom software program or a “dumb terminal.” All values are sent as printable ASCII
characters. The command parameters are delimited by a space character and the com-
mand string is always terminated with a carriage return character, (line feeds are auto-
matically stripped out by the SDPROC).
The structure of the command string:
Cmd Arg1 Arg2 Arg3 Arg4 [CR]
Where: Cmd The two or three characters command
from the table below.
Arg1 to Arg4 The command arguments from the table below.
Multiple arguments are delimited by a space character.
[CR] Carriage return character.
When a valid command is sent to the SDPROC the unit will respond as indicated in the
table. If an invalid command is sent, the unit will respond with “[string] ERROR” where
“string” refers to the characters that were received by the SDPROC (NOTE: the length
of the string has to be at least two characters long).
Several examples of both valid and invalid commands follow:
1. Turn on the check sum: CS 1[CR]
The unit will reply: CS 1 OK[CR] [LF]
2. To transmit data every 30 sec: CD 30[CR]
The unit will reply: CD 30 OK[CR] [LF]
Followed by: #1:X XX.X%I #2: XXX.X%I[CR][LF][Y Y]
(This will repeat every 30 sec and assumes a two channel SDPROC with error check-
ing enabled. XXX.X is the flow reading in % FS; I is internal reference for set point; YY
is the two character check sum).
3. Transmit Set Point to channel #2: SP 2 50.0[CR]
The unit will reply:
SP 2 50.0 OK[CR] [LF]
4. An example of an invalid command to a 2 channel SDPROC:
SP 3 106.0[CR]
The unit will reply: SP 3 106.0 ERROR:WRONG CHN#[CR][LF]
(The channel number greater than 2 and desired flow greater than 105.0 are
both invalid).