44
Remember, AA = 00 is the universal address for the TC-36-25 RS232. If the address is not correct, then the controller will
not respond to any requests.
II. Examples:
A) Set the controller to control via a computer programmable set point.
1.
The controller address, AA, is by definition 00.
2.
The write command, CC, for “SET TYPE DEFINE” is 29.
3.
A data value of “0” selects a computer communicated set value, so the eight-character send value
DDDDDDDD is 00000000.
4.
Compute the checksum (SS) by adding the hexadecimal ASCII values of the following characters: 0, 0, 2, 9, 0,
0, 0, 0, 0, 0, 0, and 0:
ASCII Character:
Hexadecimal Value:
0
30
0
30
2
32
9
39
0
30
0
30
0
30
0
30
0
30
0
30
0
30
0
30
Sum
024b
16
The 8-bit checksum is the 8 least significant binary bits of the sum, represented as 4b in
hexadecimal.
5.
Combining all of these characters into one string we send: (stx)0029000000004b(etx).
6.
If the temperature controller receives the command and the checksum is correct, it will send back:
(stx)0000000080(ack). If the checksum is not correct the temperature controller will send back:
(stx)XXXXXXXXc0(ack).
