Example Of Inverter-Inverter Communications Sequence - Omron 3G3MX2 User Manual

Network Protocol Reference
Management
Send
Inverter (01)
Receive
Send
Inverter (02)
Receive
Send
Inverter (03)
Receive
Send
Inverter (04)
Receive
All slaves receive data from the master,
but they will discard the data
if the data is not addressed to themselves.

Example of Inverter-Inverter Communications Sequence

Shown below is a communication sequence involving a total of four inverters
from station numbers 01 to 04, where the Master Inverter is one of 01 to 03.
Station register data
02 xxxx xxxx
02 xxxx xxxx
03 xxxx xxxx
03 xxxx xxxx
M
S
t1 t3
M
S
S S
S S
• For the Management Inverter, be sure to set a value other than 0 (1 sec-
ond or more is recommended) in Communication Error Timeout (C077).
When 0 is set, the Co-inverter communication function will stop if the data
sent from the Master Inverter cannot be received. If the function has
stopped, reconnect the Management Inverter or perform a reset (by turn-
ing the RS terminal ON and then turning it OFF).
• The communication timeout timer starts counting when the recipient
starts waiting for data. If data reception is not completed within the set
time, a timeout occurs (t3 in the above figure) and the operation specified
by Operation Selection on Communication Error (C076) takes place.
• If the Management Inverter is the master, the master switching command
is sent after an elapse of the silent interval + Communication Wait Time
(C078) following the sending of data by the Master Inverter (t1 in the
above figure).
• If an Inverter other than the Management Inverter is the master, the mas-
ter switching command is sent after an elapse of the silent interval + Com-
munication Wait Time (C078) following the receiving of data from the
Master Inverter (t2 in the above figure).
• If "01: Always started" is selected for Co-inverter Communication Start
Selection, the Management Inverter starts sending the moment the power
is turned on. Accordingly, any delay in the power-on timing of the other
Inverter prevents normal communication and the Management Inverter
experiences a communication timeout. If "Always started" is selected,
confirm starting of all other Inverters and then start the Management
Inverter at the end.
• Do not set 08FFh (EEPROM write) or 0901h (EEPROM write mode selec-
tion) in the recipient register.
• If any one of C096 to C100 is changed, the change will not be reflected
until the power is reconnected or a reset is performed (by turning the RS
terminal ON and then turning it OFF).
M Sent data from the master
Up to five recipients S Received data in the slave
can be specified.
S
t2
S
t3 t3 t3
M
S
t1: Silent interval + Communication Wait Time (C078)
t2: Silent interval + Communication Wait Time (C078)
t3: Communication Timeout Time (C077)
Section B-3
Master switching command
M
S
S
S
315