STP-iS2207 Series Turbomolecular Pump
MT-89E-001-C
Page 86
5
SERIAL COMMUNICATION PROTOCOL
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 query command is executed and the
SIM returns the following response (1st block).
PC->SIM
Ack or Nak F
1
F
2
SIM->PC
@
F
1
F
2
Stx
0
0
1
Sp
CHR
C
1
C
253
Etb
LRC
Then "Ack" is sent by the PC->SIM character in reaction to the response (1st block) from the SIM, the
SIM returns the following response (2nd block).
PC->SIM
Ack or Nak F
1
F
2
SIM->PC
@
F
1
F
2
Stx
0
0
2
C
254
C
n
Etx
LRC
The PC transmits "Ack" or "Nak"; then transmits the next command if necessary.
5.3.11 Broadcasting command in the RS485 multi-point connection
The START or STOP of STP pump operation command can be concurrently instructed to all the
multi-connected SIMs. Always assign 0 (HEX code "30") to network frame number. Note that there is
no response from the respective SIM.
PC->SIM
@
0
0
Stx
0
0
1
Sp
E
Parameter 1
Etx
LRC
SIM->PC
No response
Parameter
Item Data Format Remark
1 Pump operation command 8-bits hexadecimal
coded ASCII
Refer to Table 21
Pump operation command
Value
START 1
STOP 2
Table 21 - Pump operation commands