Edwards STP-iXA4507 Series User Manual

STP-iXA4507 series Turbomolecular Pump
MT-91E-001-0
Page 70
SERIAL COMMUNICATION PROTOCOL
PAG
E
70
5
5.3.2 Standard transmission frame
The transmission frame has a single block or multiple transmission blocks. The transmission block
consists of a start control character, data block Numbers (3 digits), a message (up to 255
characters), an end control character, and a checksum (LRC). The following table shows the
transmission frame if the message transmission character string is C
n
.
Transmission frame when a message is below 255 characters (n<=255):
1
2
3
4
5
5+n
5+n+1
5+n+2
ASCII
Stx
0
0
1
C
1
C
n
Etx
LRC
"Stx" and "Etx" are used as the transmission frame's start and end characters, respectively.
Transmission frame when a message exceeds 255 characters
(n = 255, m<=255, k = the number of transmission blocks):
First
1
2
3
4
5
5+n
5+n+1
5+n+2
Block
ASCII
Stx
0
0
1
C1
1
C1
n
Etb
LRC
Second
1
2
3
4
5
5+n
5+n+1
5+n+2
Block
ASCII
Stx
0
0
2
C2
1
C2
n
Etb
LRC
Final
1
2
3
4
5
5+m
5+m+1
5+m+2
Block
ASCII
Stx
k
Ck
1
Ck
m
Etx
LRC
"Stx" is used as a start character of each transmission block. "Etb" is used as an end character of the
transmission block with a message of 255 characters. "Etx" is used as an end character of the final
transmission block (the end character of the transmission frame).
5.3.3 Control command (in the RS232/RS485 single point connection)
A control command is used to transmit pump operation commands and change setting commands to
the SIM. The first character of the control command is "Sp" (a space character, HEX code "20"), and
the subsequent characters are ASCII characters corresponding to the respective function code and
parameter.
Sp
CHR
C
1
C
2
C
n
CHR: Function code character, C
1
to C
n
: Parameter.
The parameter (C1 to Cn) is a 16 bit signed hexadecimal value coded ASCII text. When a message
(the space character, the function code, and the parameter) exceeds 255 characters, input "Sp" and
CHR to only the top of the transmission blocks (the first transmission block of the transmission
frame). It is unnecessary to input them into the second and the subsequent transmission blocks.
The SIM returns the acknowledgement response character "#" when correctly processing the query
command. If not, the SIM returns the non-acknowledgement response character "!" and 3 characters
of the non-acknowledgement code are added to "!".

Edwards STP-iXA4507 Series Specifications

General

Brand	Edwards
Model	STP-iXA4507 Series
Category	Water Pump
Language	English