STP-iS2207 Series Turbomolecular Pump 
 
MT-89E-001-C
Page 80 
5
SERIAL COMMUNICATION PROTOCOL 
Then the preceding SIM->PC character is "Ack", the instructed control command is executed and the 
SIM returns the following response. 
PC->SIM
              Ack or Nak 
SIM->PC
Stx
0
0
1
# or !  Etx
LRC
 
 
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
Stx
0
0
1
Sp
CHR
C
1
  C
253
Etb
LRC
 
SIM->PC
                      Ack or Nak 
 
Next, the preceding SIM->PC character is "Ack", the PC continues instructing the control command 
(the 2nd block). 
PC->SIM
Stx
0
0
2
C
254
  C
n
Etx
LRC
 
SIM->PC
                  Ack or Nak 
 
Always assign less than 510 characters (n< 510) to the parameter so that the message is less than 
512 characters. 
Then the preceding SIM->PC character is "Ack", the instructed control command is executed and the 
SIM returns the following response. 
PC->SIM
              Ack or Nak 
SIM->PC
Stx
0
0
1
# or !  Etx
LRC
 
 
The PC transmits "Ack" or "Nak"; then transmits the next command if necessary. 
 
5.3.4  Query command (in the RS232/RS485 single point connection) 
A query command is used to read the pump operation state and setting values. The first character of 
the  query  command  in  the  RS232/RS485  single  point  connection  is  "?"(HEX  code  "3F"),  and 
succeeding  characters  are  ASCII  characters  corresponding  to  the  respective  function  code  and 
parameter. 
?  CHR
C
1
  C
2
          C
n
 
 
CHR: Function code character, C
1
 to C
n
: Parameter