Varec TankGate Interface 8315 Series - Manual (Page 46)

Software Description Tank Gate Interface
36 Installation and Operations Manual
The DataMode can also control if the data is changed to 0xFFFF if the data is invalid. The Filter
parameter is compared to the PntStatus of the PntRef parameter. If bits in the PntStatus match
bits in the Filter, the data is considered invalid and the a read from a modbus host will result in
the data being set to 0xFFFF.
When Block Read or Write requests are received, then the way in which the Modbus Slave
protocol handler responds is determined by the Size parameter.
Size Parameter
A range of addresses can be specified by setting the Size parameter. This sets the indexing
mode to Number Indexing, which means that Block Read/Write requests from the Hosts are
handled by stepping through the points number by number. For example, if Addr1 is 100, and
PntRef1 is MSTX.00.RawValue, then a Block Read to address 100 with a length of 8 will return
the values, MSTX.00.RawValue, MSTX.01.RawValue, ... MSTX.07.RawValue. Setting the Size to 1
does not limit the read to 1 parameter, rather it indicates that block operations will be processed
by stepping through points by incrementing the number, starting with parameter specified by
the PntRef.
4.4.7 Integer Register (IREG)
The Integer Register point provides two bytes of storage. It is often used for inter-
point communications where no other means is provided.
Parameters
The database parameters used by the IREG point are listed and described below:
4.4.8 Modbus Gateway (MODGW)
The Modbus Gateway provides dynamic and statistical information for the
communications between the 8300 series Tank Gate Interface and the Modbus
masters.
Parameters
The database parameters used by the MODGW point are listed and described below:
Configuration Parameters Function
Tag A Tag can contain 15 bytes of data and can include any printable ASCII
character. Tags can be used to identify points indicating the use of the
point.
Dynamic Parameters Function
Value Integer (2 bytes) value