SMC Networks THERMO-CON HEC001 Series, Руководство по связи, Страница: 13 / 25

Communication Format
HEC 3-3
<Specifying unit>
Host
→
SOH UT ENQ COM Check sum CR
(H) (L)
←
Thermo-con
SOH UT STX COM Data ETX Check sum CR
10
1
10
0
10
-1
10
-2
(H) (L)
Host
→
ACK UT CR (Possible to omit)
･
COM indicates communication command.
･
UT indicates unit No. of each Thermo-con. Unit No. is the No. to identify each Thermo-cons when
2 or more Thermo-cons are linked by communication. Set this No. with second mode of Thermo-
con within O-F. (UT is the code adding 30H to unit No.. 30H---3FH.)
･
As for symbols at communication, minus is indicated by “-“ (2DH by ASCII code) and plus is
indicated
by “0” (30H by ASCII code).
･
In case of setting temperature and offset with communication, data out of set range isn’t
memorised. (If communication format is correct, ACK returns.)
･
When writing in EEPROM is specified, changed data is memorized in EEPROM each time. Since
writing life of EEPROM is (
approx. 1 million times)
, EEPROM is changed only when data is changed.
3.4
Calculation of Check Sum
Calculation range ---------------- From the second byte to ETX
when there is no ETX, add before check sum.
Calculating method---------------Take out the lower 1 byte of the total.
eg.) Set temperature to 30 deg.C (without unit specified)
STX 31H 33H 30H 30H 30H ETX 3FH 34H CR
Total F4H
eg.) Read Thermo-con internal sensor of unit No.2
SOH 32H 05H 32H 36H 39H CR
Total 69H
Note) Check sum is not ASCII code.
Data of UT and Check Sum
Character data 0
…9 Ａ Ｂ Ｃ Ｄ Ｅ Ｆ
ASCII
30H…39H
41H 42H 43H 44H 45H 46H
UT and check sum
30H…39H(ditto)
3AH 3BH 3CH 3DH 3EH 3FH