8300 | 8315 L&J Tankway Software Description |
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Address | Type | Number | Parameter | Data Type |
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5018 | WV1900 | 1 | Status | HEX |
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5019 | WV1900 | 1 | PntStatus | IHEX |
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5020 | WV1900 | 1 | Elapse | TIME |
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4.5.3GWBLK method
The GWBLK is the preferred means to address data in the TankGate. The GWBLK has a great deal of flexibility. Data can be scaled, or grouped using the GWBLK. The Gateway Block (GWBLK) allows the user to specify data address and point reference combinations. This allows the TankGate to be used with an existing system that is already configured. The TankGate can be tailored to meet the needs of the Host. In some cases, the Host system may have some constraints in the use of its Modbus scanner that make it necessary to use a GWBLK. In this mode, the user defines a GWBLK point and specifies which database parameter will correspond to a particular data address. When a request from a master is received, the Modbus Slave protocol handler will first search for any GWBLK points and determine if the data address of the request is specified in one of the GWBLK points. If the data address is contained in a GWBLK point, then the corresponding point reference is used to provide the data for the reply to the master. If the data address is not in any GWBLK point, then data will be read using the prevailing Address Mode.
The Gateway Block (GWBLK) allows the user to specify data address and point reference combinations. The GWBLK acts as a lookup table for data items in the TankGate. The user defines a GWBLK point and specifies which database parameter will correspond to a particular data address. When a request from a master is received, the Modbus Slave protocol handler will search for any GWBLK points and determine if the data address of the request is specified in one of the GWBLK points. If the data address is contained in a GWBLK point, then the corresponding point reference is used to provide the data for the reply to the master.
The procedure for using the GWBLK is given below:
•Add a GWBLK point. Depending upon the addressing requirements of the host system, it may be necessary to add additional GWBLKs.
•Configure the GWBLK by setting the Address, PntRef and Size parameters to the parameters of interest in the TankGate. Refer to the following example:
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