Omron V600 Series Operation Manual page 21

Data Carrier Motion and Command Conditions
3-1-6 Polling Auto Function with 1 to N Connection (V600-CA2A-V
Only)
8. Once processing is completed, the ID Controller sends a response to the
host computer indicating that the processing indicated by the query sub-
command has been completed.
This section describes command processing when one R/W Head is connected
to each of two ID Controllers (Unit 1 and 2). In the case of normal auto com-
mands, the ID Controller does not return a response until the DC comes close to
the specified R/W Head. This means that until the response is sent, the commu-
nication path with the host computer remains in the busy condition, and the host
computer cannot send commands to the other R/W Head. However, the polling
auto command enables the ID Controller to return the response when requested
by the host computer. Thus, the busy condition on the communication path to the
host computer is cleared, and the host computer can then send commands to
the other R/W Head.
(Host Computer) (ID Controller)
Polling auto
command
(Unit 1
R/W Head 1) Response
Polling auto
(Unit 1
command
R/W Head 1)
(Unit 2
R/W Head 2)
Response
(Unit 2
Sub-
R/W Head 2)
command
(Inquiry to unit 1
R/W Head 1)
Response
Sub- (Not close to Unit 1
command R/W Head 1)
(Inquiry to unit 2
R/W Head 2)
Response
(Not close to Unit 2
R/W Head 2)
Read/Write
processing
(Unit 1
R/W Head 1)
Sub-
command
Response
(Inquiry to unit 1
R/W Head 1)
(Unit 1
R/W Head 1
processing
completed)
Section
(DC)
Not close
Not close
Not close
Not close
DC
Passes on
3-1
19