Watlow Series 734 Data Communications - Manual (Page 16)

How to Use Data Communications
16
WATLOW Series 733/734
ANSI X3.28 "?"
Figure 9 -
ANSI X3.28 "?"
Command Example.
<ETX>
ASCII
Characters
HEX
Value
1
41 4C 31
Space
?
3F 20
A
L
<STX>
02 03
Optional
Carriage
Return
O
4F
Response from the Series 733/734:
<ACK>
The hex response string is:
06
• You'll find the the complete list of "=" command arguments (prompts and value
limits) in Table 5, Pages 17-19.
ANSI X3.28 "?" Command Example
You need to know the Alarm 1 Low value (A1LO). The "?" uses a variation of the
message syntax shown just below. This syntax requires the protocol start of
text and end of text characters.
"?" command syntax with ANSI X3.28 Protocol:
<STX> ?<space> <data.1> <ETX>
Enter in ASCII:
<STX> ? <space> <A1LO> <optional carriage return> <ETX>
The hex string will be:
023F2041314C4F03
First response from the Series 733/734:
<ACK>
The <ACK> hex response string is:
06
Your computer's confirming response:
<EOT>
The <EOT> response hex string is:
04
Second response from the Series 733/734:
<STX> <current A1LO value> <carriage return> <ETX>
The hex string is:
023530302003
Your computer's next response:
<ACK> or < NAK> (if the message needs to be repeated).
The hex string is:
06 or 15
Final response from the Series 733/734:
<EOT>
The hex string is:
04
<STX>
ASCII 5
Characters 0
0
<cr><ETX>
HEX
Value
02 35 30 30 20 03