Omron MX2 Series User Manual page 448

8 Communications Functions
Example of Co-inverter Communication Sequence
The sequence diagram below shows co-inverter communication among four inverters with station num-
bers from 1 to 4, where Stations No. 1 to 3 are set as the master inverter.
Management
Inverter Station No. 1
Inverter Station No. 2
Inverter Station No. 3
Inverter Station No. 4
All slaves receive data from the
master but discard it if not destined
to them.
• Be sure to set the Communication Error Timeout Time (C077) to other than 0.00 (1 second or longer
is recommended) on the management inverter. When this parameter is set to 0.00, the inverter's
communications function will stop if no data is received from the master. If it stops working, cycle the
power supply of the management inverter.
• The communications error timeout timer starts when the inverter starts waiting for data reception and
times out when it cannot complete data reception within the set time. If a timeout occurs, the inverter
performs the operation set in the Operation Selection on Communication Error (C076). (t3 in above
diagram)
• When the management inverter is the master, the master switching command will be sent with a wait
time of "silent interval + Communication Wait Time (C078) after the master sends data. (t1 in above
diagram)
• When an inverter other than the management inverter is the master, the master switching command
will be sent with a wait time of "silent interval + Communication Wait Time (C078) after receipt of data
sent from the master inverter. (t2 in above diagram)
• When the Co-inverter Communication Start Selection (C100) is set to 01 (Constant communication),
the management inverter starts sending data as soon as the power supply is turned on. Therefore, if
the power-on timing of any other inverter is delayed, the communications cannot be established nor-
mally, which results in a communications timeout error on the management inverter. When you set
this to 01 (Constant communication), check that the startup of the other inverters is completed and
power on the management inverter finally.
• Do not set 08FF hex (EEPROM Write) or 0901 hex (EEPROM Write Mode Selection) in the recipient
registers. Doing so causes the co-inverter communication session to stop in the EEPROM write pro-
cess.
• After changing any of the C096 to C100 data, be sure to cycle the power supply to apply the
changes.
8 - 36
Station No. register data
02 xxxx xxxx
02 xxxx xxxx
03 xxxx xxxx
03 xxxx xxxx
Send
M
Receive
t1 t3
Send
Receive S
Send
Receive S
Send
Receive S
Up to 5 recipients
can be specified.
S
t2
M
t3 t3
S
S
t1: Silent Interval + Communication Wait Time (C078)
t2: Silent Interval + Communication Wait Time (C078)
t3: Communication Error Timeout Time (C077)
Multi-function Compact Inverter 3G3MX2-V1 User's Manual (I585-E1)
Data sent from master
M
Data received by slave(s)
S
Master switching command
M
S
S S
t3
M
S
S S