User's Manual
Table Of Contents
- Modbus/TCP Communications
- 7-1 Outline
- 7-2 Message Formats
- 7-3 RF Communications Command Options
- 7-4 Communications Procedure
- 7-5 Commands
- 7-6 V780 Command Details
- 7-6-1 Single-access Communications Commands
- 7-6-2 Multiaccess Communications Commands
- 7-6-3 Modbus Expansion Communications Commands
- 7-6-4 Reader/Writer Control Commands
- 7-6-5 Reader/Writer Setting Commands: Network Settings
- 7-6-6 Reader/Writer Setting Commands: Communications Settings
- 7-6-7 Reader/Writer Setting Commands: Device Settings
- 7-6-8 Maintenance Commands: Device Information
- 7-6-9 Maintenance Commands: Log Information
- 7-6-10 Maintenance Commands: RF Communications Information
7 - 15
7 Modbus/TCP Communications
UHF RFID System V780-series Reader/Writer User’s Manual (Z389)
7-4 Communications Procedure
7
7-4-4 RF Tag Communications Command Procedure for Multiaccess Communica-
tions
With a normal multiaccess RF Tag command, two commands are used to exchange the data, one to set
communications and another to get the results.
1 Sending the Command to Set Communications
First, send the command to set communications.
If the Reader/Writer detects even one RF Tag, the results of execution are returned as a normal
response.
If no RF Tags were detected, an RF Tag missing error is returned.
2 Sending the Command to Get the Results
Send the command to get the results.
When you execute the command to get the results, the results of communications with the first
RF Tag that was detected will be returned. The communications results will contain the number
of RF Tags detected, the error code, and, for READ DATA, the EPC code.
If the option is specified, the reception level information is also attached.
3 Repeatedly Getting the Results
Execute the command to get the results once for every RF Tag that was detected.
The number of RF Tags that was detected by the Reader/Writer is included in the response to
the command to get the results. Repeatedly send the command until the number of RF Tags in
the response is 1.
Using a Normal Command (FC03 or FC16)
Host device
(client)
Reader/Writer
(server)
RF Tag A
RF Tag B
RF Tag C
SET MULTIACCESS DATA READ
communications command sent.
GET MULTIACCESS DATA READ RESULTS communications command sent.
GET MULTIACCESS DATA READ RESULTS communications command sent.
Communications field
RF Tag memory
read/written.
Error code Read data
Number of RF Tags: 3
EPC code
+ Reception level
Error code Read data
Number of RF Tags: 2
EPC code
+ Reception level
Response returned.
Response returned.
Response returned.
GET MULTIACCESS DATA READ RESULTS communications command sent.
Error code Read data
Number of RF Tags: 1
EPC code
+ Reception level
Response returned.
Command execution
Timeout (TMO)
RF Tag A
communications
results
RF Tag B
communications
results
RF Tag C
communications
results