Exchange tag values between eWONs using Instant Value
Sometimes it is necessary to exchange data between 2 eWONs.
For example to send data from a PLC to another PLC located on an other site.
To exchange data between 2 eWONs the instant values feature can be used. Instant value means values of Tags at a given time. The Tag's instant values are stored in the inst_val file on the eWON.
It is also possible to write by FTP an instant value file on the eWON. The values of the Tags contained in this file will then be used to change the value of the corresponding Tag on the eWON.
If a Tag is not found, then it will be ignored.
The Export Block Descriptor "[$dtIV $ftT $flA]" extracts from the eWON the Instant Values for every Tag belonging to Group A.
The PUTFTP function will send the inst_val.txt to the other eWON at address 10.0.120.199 using username/password adm/adm.
Note: Older eWON versions doesn't allow the specification of the FTP server directly in the PutFTP command .
For these versions you'll have first to specify the FTP server in the General Settings section of the eWON.
To test the exchange of data, you'll first have to create Tags on both eWON having the same name. So for example create on the 1 st eWON Tags called Tag1 and Tag2 belonging to Instant Value Group A and create on the 2nd eWON also Tags called Tag1 and Tag2.
The association of a Tag to a specific Instant Value Group (A, B, C, D) must be done for every Tag in the Tag Setup configuration page.
ExportInstVal: PUTFTP "inst_val.txt", "[$dtIV $ftT $flA]", "adm:email@example.com:21" LogEvent "Instant values for Tags of Group A exported to 10.0.120.199",100 End