TE Technology TC-24-25 - Manual (Page 24)

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Send the set temperature of 100.0 °F to the controller at address 01.
1. The controller address, AA, is by definition 01.
2. The control command, CC, for “FIXED DESIRED CONTROL SETTING” is 1c.
3. Multiply the desired set-point temperature by 10 (100.0 converts 1000d).
4. Convert 1000d to hex (03e8h) and add on leading zeros to make the eight-character
send value DDDDDDDD (000003e8).
5. Compute the checksum (SS) by adding the ASCII values of the following characters:
0, 1, 1, c, 0, 0, 0, 0, 0, 3, e, and 8:
ASCII Character:
Hex Value:
0 30 hex
1 31 hex
1 31 hex
c 63 hex
0 30 hex
0 30 hex
0 30 hex
0 30 hex
0 30 hex
3 33 hex
e 65 hex
8 38 hex
Sum 02b5 hex
The 8-bit checksum is the 8 least significant binary bits of the sum, represented as b5 in
hex.
6. Combining all of these characters in one string we send: (stx)011c000003e8b5(etx).
7. If the temperature controller receives the command and the checksum is correct, it will
send back: (stx)000003e8c0(ack). If the checksum is not correct the temperature
controller will send back: (stx)XXXXXXXXc0(ack).
Read the actual temperature of the control thermistor (INPUT1) from the controller at address 01.
1. Let’s assume the actual temperature is 25.0 °C, and the working units have been
defined as °C. This means that the controller will return a value in °C.
2. The controller address, AA, is by definition 01.
3. The control command, CC, for “INPUT1” is 01 hex.
4. There is no send value, so we can just calculate the checksum (SS) by adding the
ASCII values of the following characters: 0, 1, 0, and 1:
ASCII Character: Hex Value:
0 30 hex
1 31 hex
0 30 hex
1 31 hex
Sum 00c2 hex
The 8-bit checksum is the 8 least significant binary bits of the sum, represented as
c2 in hex.
5. Combining all of these characters in one string we send: (stx)0101c2(etx).
6. If the temperature controller receives the command and the checksum is correct, it will
send back: (stx)000000fae7(ack). The e7 at the end of the string is the checksum of
“000000fa”. The value ”000000fa” hex converts to 250 in decimal. This number,
when divided by 10 is 25.0, is the temperature in °C. As in the other examples, if the