Selecta VACIOTEM-T - Page 28

MANUAL DE INSTRUCCIONES CODIGO 80152 REV E DIC 2019 (Sujetas a modicaciones sin previo aviso) Pag.: 28
J.P. SELECTA s.a.u. Ctra. NII Km 585.1 Abrera 08630 (Barcelona) España Tel 34 937 700 877 Fax 34 937 702 362
e-mail: selecta@jpselecta.es - website: www.grupo-selecta.com
LRC ERROR CHECKING FIELD
FrameincludesatransmissionerrorcheckingeldcalledLRC.The
eldsizeis2bytes.Thiseldiscalculatedbythesenderdevice
and includes it on the frame. The receiver device also calculates
LCR value. If calculated value is equal than the transmitted LCR
value, transmission was good.
LRC calculation procedure:
1. Convert each character on its hexadecimal value.
2. Add.
3. Takethesmallestbyte(tworstcharactersstartingfromright
hand side).
4. Subtract from FF on previous result.
5. Add 1.
LRC CALCULATION EXAMPLE
ASCII HEX
# 23
0 30
1 31 #01SVT<BL>+098,037<CR><LF>
S 53
V 56
T 54
<BL> 20
+ 2B
0 30
9 39 FF
8 38 - C9
, 2C 36
0 + 30 + 1
2C9 LRC = 37
•  «Get»commandsalwaysendsby«?»
•  Charactersalwaysincapitalletters.
•  Usespacesonlywhenindicatedby<BL>.
•  Decimalseparatoris«,».
CONNECTION CABLE
It could be found in any electronic components specialized shop:
Cable Null - 9 pins modem
Connectors in both cable sides are 9 pins female.
PC Device
1 7, 8
2 3
3 2
4 6
5 5
6 4
7 1
8