Chapter 4 Explanation of Functions

4.4.1 Communication in ASCII mode

(1) Communication protocol

The communication between the inverter and external control system is based on the following protocol:

(1)

External control system

Inverter

C078

(2)

Time

Waiting time (to be set with the digital operator)

(1): Frame that is sent from the external control system to the inverter

(2): Frame that is sent from the inverter to the external control system

The inverter sends frame (2) as a response always after receiving frame (1). The inverter does not actively output any frame to the external control system.

The following table lists the frames (commands) used for communication:

Commands

Command

Function

Broadcast to all

Remarks

stations

 

 

 

00

Instructs the inverter to drive the motor (for

 

forward or reverse rotation) or stop the motor.

 

 

 

 

01

Sets the inverter output frequency.

 

02

Turns specified intelligent input terminals on

 

or off.

 

 

 

 

03

Reads all monitored data.

×

 

04

Reads the inverter status.

×

 

05

Reads a specified setting item.

×

 

06

Writes data to a specified setting item.

×

 

07

Initializes specified settings.

This command can operate only

 

 

 

08

Instructs the inverter to drive the motor (for

 

when "01" or "02" has been specified

for the initialization mode (b084).

forward or reverse rotation) or stop the motor.

 

 

(Otherwise, only the trip history data

 

 

 

 

Checks whether set data can be stored in the

 

is cleared.)

09

×

 

EEPROM.

 

 

 

 

0A

Stores set data in the EEPROM.

 

0B

Recalculates the constants set in the inverter.

 

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Hitachi SJ700-2 instruction manual Communication in Ascii mode