Data Format - Omron E5AN User Manual

CHAPTER 4 Sysway (E5 J,

4.1 Data Format

J Command frame format
J FCS calculation example
Start
character
@(40H)
FCS = 40H ¨ 30H ¨ 30H ¨ 52H ¨ 58H ¨ 30H ¨ 31H = 4BH
Calculation result 4BH is converted to ASCII at each digit and set to the FCS area.
4 ! 34H
B ! 42H
The ¨ symbol indicates exclusive OR operation and the H indicates hexadecimal code.
4--2
X format) COMMUNICATIONS PROCEDURES
Commu- Header Data
nications code
code
unit No.
@
FCS calculation range
@ Character (40) that indicates the start of block format
Communications A number within the range 0 to 99 can be set in BCD. No
unit No. response will be returned if a number other than this is set.
Header code 2-character alphabet code that indicates the command type
Data code Set "02" only when reading and writing alarm value 2. Other-
wise, set "01".
Text This area stores read values, write values and status. The con-
tent of this area varies according to the command.
FCS The FCS (Frame Check Sequence) is formed by converting the
value obtained by converting the exclusive OR of @ to the last
text character into ASCII characters.
Terminator Indicates the end of the block format.
Comprises "*" and CR (Character Return 0D)
The FCS is formed by converting the 8-bit value obtained by converting
the exclusive OR of start character "@" up to the last text character into
two ASCII characters, and setting this to the FCS area.
Communications
Header code
unit No.
0(30H) 0(30H) R(52H)
Text FCS
Data code
X(58H) 0(30H) 1(31H)
Termi-
nator
CR
*
FCS
4(34H) B(42H)