Chapter 11 Communication Specifications

11.6.2 Port 2

Port 2 of the MICRO-EH is a communication port that uses either the RS-422 or RS-485 protocol as interface. It is also a dedicated port with which to perform communication by the H series dedicated procedure (high protocol), which allows 1:n station communication. Figure 11.6 and 11.7 show examples of port 2 connections for 1:n station communication. Moreover, the connection for communicating 1:1 is performed by connecting only the first CPU in the figure below.

(1)In case of RS-422

RD (-) RD (+) SD (-) SD (+)

Host

(13) SDP

(13) SDP

(13) SDP

(12) SDN

(12) SDN

(12) SDN

(11) RDP

(11) RDP

(11) RDP

(10) RDN

(10) RDN

(10) RDN

 

MICRO-EH

MICRO-EH

MICRO-EH

(1st CPU)

(2nd CPU)

(32nd CPU)

Figure 11.6 Connection for 1:n station communication by RS-422

(2)In case of RS-485

Host

RD (-)

RD (+)

SD (-)

SD (+)

 

MICRO-EH

 

MICRO-EH

 

(1st CPU)

 

(32nd CPU)

(13) SDP

 

(13) SDP

 

 

(12) SDN

 

(12) SDN

(11) RDP

(10) RDN

(11) RDP

(10) RDN

 

 

Twisted pair cable

A

B

Relay terminal block

Relay terminal block

Relay terminal block

Figure 11.7 Connection for 1:n station communication by RS-485

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Hitachi NJI-350B manual Case of RS-422, Connection for 1n station communication by RS-485 11-9