Watlow Series 734 Data Communications - Manual (Page 12)

How to Use Data Communications
12
WATLOW Series 733/734
XON/XOFF "="
Figure 6 -
XON/XOFF "="
Command Example.
ASCII
Characters
HEX
Value
1
Space
5
0
0
41 4C 31 20 35 30 30
=
3D 20
A
L
0D 4F
O
How To Start and Stop Communicating
with the Series 733/734 and XON/XOFF
Starting communications with XON/XOFF Protocol is simple. You just configure
your computer to agree with the Series 733/734 communication prompts and open
its serial communication port in software. Then begin to "talk" by transmitting a
message to the Series 733/734. You stop communicating with XON/XOFF Proto-
col simply by ceasing to send messages.
XON/XOFF "=" Command Example
The general command syntax is the one you've already seen. Each command
uses a slightly different variation of it, depending on the number of arguments
required for a message.
• You want to change the Alarm 1 Low (A1LO) value to 500°. The "=" command
will do the job.
The syntax with XON/XOFF Protocol requires an ending Carriage Return
.
"=" Command Syntax with XON/XOFF Protocol:
= data.1 data.2
With the "=" Command, data.1 is the Series 733/734 prompt, in this case Alarm 1
Low, A1LO. Data.2 is the value you want to set for that prompt, in this example,
500.
Enter in ASCII:
= A1LO 500
The hex string will be:
3D2041314C4F203530300D
Response from the Series 733/734:
It sends an "XOFF" when a carriage return is received and then an "XON" when
the unit is done processing the command.
• The complete list of Commands is in Table 5, Pages 17-19.
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