Control Command In The Rs485 Multi-Point Connection - Edwards STP-iS2207 Series Instruction Manual

5.3.9

Control command in the RS485 multi-point connection

5
The control command to be used when a pump operation instruction or a setting change instruction is
transmitted to the SIM and is arranged in the order specified below. The top is "Sp" (space character,
HEX code "20") and ASCII characters corresponding to the respective function code and parameter
follow.
Sp CHR
CHR: Function code character, C
Parameter (from C
message (a space character, a function code, and parameter) exceeds 255 characters, input "Sp" and
CHR to the top transmission block only (the first transmission block of the transmission frame). It is not
necessary to input them to the second and succeeding transmission blocks.
The SIM returns the acknowledgment response character "#" when the control command is
processed normally. If not, the SIM returns the non-acknowledgment response character "!" and 3
characters of the non-acknowledgment code are added to "!".
Transmission frame when data is transmitted to one block (a message is less than 256 characters):
Designate the control command on the PC.
PC->SIM @ F
SIM->PC
Always assign less than 254 characters (n< 254) to the parameter so that the message is less than
256 characters.
Next, the preceding SIM->PC character is "Ack", the instructed control command is executed and the
SIM returns the following response.
PC->SIM
SIM->PC @ F
The PC transmits "Ack" or "Nak"; then transmits the next command if necessary.
Transmission frame when data is transmitted to two blocks (message is more than 256 characters
and less than 512 characters):
Designate the control command (the 1st block) on the PC.
PC->SIM @ F
SIM->PC
MT-89E-001-C
Page 84
STP-iS2207 Series Turbomolecular Pump
C C
1 2
to C : Parameter
1 n
to C ) serves as 16 bits signed hexadecimal value coded ASCII text. When a
1 n
<- Less than 256 chr.->
F Stx 0 0 1 Sp CHR C
1 2
F Stx 0 0 1 # or !
1 2
F Stx 0 0 1 Sp CHR C
1 2
C
n
C Etx LRC
1 n
Ack or Nak
Etx LRC
C Etb LRC
1 253
Ack or Nak F F
1 2
F F
1 2
Ack or Nak F F
1 2