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Tank Gate Interface
64 Installation and Operations Manual
5.6.2 Application
The MFIO point continually scans the Allen Bradley Flex I/O device, using the ID parameter. Chan
determines which 8203 Dual RS-485 Communications Interface and Channel is used for
communications to the Allen Bradley. An MFIO point is needed for each device connected to the
8303 TGI. Up to 8 Registers can be read with each MFIO point. The BaudRate and ComParams
values must match the communications parameter of the Allen Bradley module.
Each point can read up to 8 consecutive register values, and write to 3 configuration addresses.
The ReadCmd parameter determines the command to read data and the WriteCmd parameter is
the command used for write operations. The Addr1 and Size1 parameters determine the read
register values, while the Addr2-4 and Value2-4 determine the configuration values that can be
written to the Allen Bradley. Set the Addr1 and Size1 parameters to read the data from the
device. The response will be placed in the Value1-Value8 parameters. For example, if Addr1 =
1000 and Size1 = 6, then the MFIO point will read 6 values and place the data in Value1- Value6.
Likewise, if configuration data needs to be set, Addr2 - Addr4 sets the address to be written to,
and Value_2 – Value_4 is the data written to that address. For example, if Addr2 = 1201 and
Value_2 is 0x2222, a value of 0x2222 will be placed in the register address 1201.
8203 TGI software points may begin scanning when the point is created, or when the correct
Channel number is assigned. Which of these events begins the scanning process varies with
each point.
Maxtime Specifies the maximum time (in secs) between automatic Change of State
responses being sent to the Host. Report must be set to either Low or High for
the Value parameter to be sent in response to a Change of State Request. A
value of 0 disables this option. Non-zero values cause responses to be sent
even if the value has not changed since the last message. The maximum is
65535 seconds. The default is 240.
Watchdog Enables the watchdog task on the Motherboard. The watchdog task monitors
the MBMFT point on the 8203 Dual RS-485 Communications Interface Module
and verifies it is scanning for gauges. If the 8203 Dual RS-485 Communications
Interface Module fails, the 0x0010 and the 0x0001 bits of the PntStatus will be
set to indicate the failure.
Dynamic Parameters Function
Value1 Analog Value 1
Value2 Analog Value 2
Value3 Analog Value 3
Value4 Analog Value 4
Value5 Analog Value 5
Value6 Analog Value 6
Value7 Analog Value 7
Value8 Analog Value 8
PntStatus Byte value indicating status of point. Values are:
0x0001: Gauge Not Responding
0x0010: Failure of the Model 8203. This bit is set if the Watchdog task on the
Motherboard determines that the Model 8203 has stopped updating.
Elapse Time of last scan.
PntCheckSum CRC-16 Checksum for point’s static Configuration Parameters
Configuration Parame-
ters Function