eWON General Reference Guide - eWON wiki

5.4.3.1 ValueName
General Reference Guide IO Servers Configuration
(*) Important: To avoid loss of precision due to Integer to float conversion, choose the right storage DataType for your Tag.
See "DataType of Tags" on page 75
• Bit access modifier:
In any of the above items, it is possible to access a single bit (except for float items).
#x must be appended to the Value Name. (Bit index goes from 0..31)
The syntax can be used for reading bits and for writing them as well.
Example:
DB1W13#3 represents bit 3 of W13 in DB 1
REM:
Bit index range depends on a referenced item (for W, bit index maximum value is 15)
• Status register:
The STATUS Tag is a special Tag that returns information about the current state of the communication for a given device. As for other Tags, the
status Tag ValueName is composed of:
Status, Global Device Address
• You can define a status Tag for each PLC used.
• If you use the status address, the Tag must be configured as analog.
0
Syntax Description
Automatic
Tag type
DBxBy Data block x Byte offset y (0-255) DWord
DBxWy Data block x Word offset y (0 - 65535) DWord
DBxFy Data block x Float offset y (+-3.4e38) Float
DBxDy Data block x DWord offset y (-2147483648->2147483647) (*) Integer
MxB Memento x as byte DWord
MxW Memento x as word DWord
MxF Memento x as real Float
MxD Memento x as double (*) Integer
Tx Timer x (0-65535) DWord
Cx Counter x (0-65535) DWord
Table 73: value names for NETMPI addresses
Communication not initialized. Status UNKNOWN.
If no Tag is polled on that device address, the communication status is unknown.
1 Communication OK.
2 Communication NOT OK.
Table 74: Tag Status meaning
5.4.3.2 Device Address
The device address is either appended to the ValueName in the Item Name definition, or entered in the Topic global address fields.
The device address is composed of: RemoteStationAddress,eLinkIpAddress:
• RemoteStationAddress: is the PLC’s MPI address
• eLinkIpAddress: is the eLINK IP address.
Important:
If the PLC address is defined at the Topic level, it can be omitted in the Tag definition. In that case the Tag name will only contain
the "ValueName".
If the PLC address is specified at the Topic level, it will replace any address defined Tag by Tag.
RG-001-0-EN ver 1.14 eWON® - 02/05/2012 - ©eWON sa Page 104