g.Setpoint Initial Mode – ‘sim’
As with the value, the setpoint mode set using the ‘spm’ command (above) is a volatile setting. Again this command provides a way of setting an initial startup mode for the setpoint on power up of the THCD. It takes one parameter which is a number between 0 & 2, identifying the initial mode, as follows:
0 = AUTO mode 1 = OPEN mode 2 = CLOSED mode
The current mode of the setpoint can be retrieved by using the query ‘spm?’. The returned data is: SP INIT MODE: (<x>) <mode string>
… where …
<x> = 0, 1, or 2 and <mode string> = AUTO, OPEN, or CLOSED respectively.
5.4.Serial Commands
a)Serial Baud Rate – ‘bra’
The serial baud rate (BR) can be set using this command. Any value can be entered as the parameter and the THCD decides on the actual baud rate using the following criteria:
Parameter value (BR) | Actual baud rate |
|
|
BR < 14400 | 9600 |
|
|
14400 ≤ BR < 28800 | 19200 |
|
|
BR ≥ 28800 | 57600 |
|
|
When changing baud rate using serial commands, the THCD will give the usual response to the command at the current baud, then change baud rate and give the !<address>!o!↵ response at the new baud rate. Host front ends can therefore monitor for this to confirm that the baud rate has changed. If this command is used with
To retrieve the current baud, use the query ‘bra?’. Returned data is:
BAUD: <baud rate>
b)Serial Communication Protocol – ‘pro’
This command switches the serial protocols between RS232 & RS485. The parameter passed should be one of the following:
0 = RS485
1 = RS232
To retrieve the current protocol setting, use the query ‘pro?’. Returned data is:
PROTOCOL: <protocol> … where
<protocol> = 0 or 1 as above.
c)Serial Communication Address – ‘add’
As mentioned previously (section 4.2), all commands are prefixed with an address letter. This command allows you to change that address. Valid addresses are a through h. When the THCD replies to the command, the first line will contain the old address and the response line will contain
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