Edwards STP-iXA3306B, Руководство пользователя

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STP-iXA3306 Series Turbomolecular Pump
MT-82E-001-H
Page 82
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5.2.2 Connecting the RS485
Make sure the followings when using the serial port COM1 with RS485 or COM2.
•
A connection condition is 1 on 1 (single point connection) or 1 on N (multi-point connection).
A maximum number of 32 SIMs are connectable in the multi-point connection.
•
After receiving commands, SIM will return a response approximately 5 msec later at the shortest.
Connect the PC of which transmit/receive switch time is 5 msec or less.
•
Use twisted-pair wire in communication cable. The extended communication cables should be
1.2 km or less.
•
Connect the terminator to the communication devises at both ends of the transmission line. The
terminator (120
Ω, 0.25 W) is required for connection.
(STP-iXA3306 series does not have terminator setting function)
PC
7 (D
–)
8 (D+)
120
Ω
120
Ω
SIM
(connector X3
or X4)
a) RS485 single point connection
PC
7 (D
–)
8 (D+)
120
Ω
7 (D
–)
8 (D+)
120
Ω
7 (D
–)
8 (D+)
SIM 1
(connector X3
or X4)
SIM 2
(connector X3
or X4)
SIM N
(connector X3
or X4)
b) RS485 multi-point connection
Figure 42 - RS485 connections