Configure the Modbus Point Scanner Configuration
The Modbus tab on the Forms of SCADAPack x70 Modbus Point Scanners contains a Configuration section. Use the Configuration section to configure the general point scanning properties.
Modbus Data Type
Use this combo box to specify the format of the point value. The SCADAPack x70 device automatically determines the Object Type (Analog, Digital, or Counter) based on the selected Modbus Data Type. The Object Type determines the type of database item to which the specified Modbus registers are mapped.
The Modbus Data Type options comprise a combination of the following:
Discrete (Digital)
The value is formatted as a discrete number (digital points only).
INT
The value is formatted as signed 16-bit data. Each INT comprises 1 Modbus register (analog points only).
UINT (Analog)
The value is formatted as unsigned 16-bit data. Each UINT comprises 1 Modbus register (analog points only).
This is the default option.
DINT
The value is formatted as signed 32-bit data. Each DINT comprises 2 Modbus registers (analog points only).
When the Scanner's Operation is set to 'Write' or 'Read/Write', this option is only available if the associated Modbus Slave Device's Write Holding Registers property is set to 'Multiple (Function Code 16)'. For information about configuring the latter property, see Configure Modbus Slave Device Configuration Settings. For information about configuring the Modbus Slave Scanner's Operation property, see Configure the Modbus Scanners Settings.
UINT (Counter)
The value is formatted as unsigned 16-bit data. Each UINT comprises 1 Modbus register (counter points only).
UDINT
The value is formatted as unsigned 32-bit data. Each UDINT comprises 2 Modbus registers (counter points only).
When the Scanner's Operation is set to 'Write' or 'Read/Write', this option is only available if the associated Modbus Slave Device's Write Holding Registers property is set to 'Multiple (Function Code 16)'. For information about configuring the latter property, see Configure Modbus Slave Device Configuration Settings. For information about configuring the Modbus Slave Scanner's Operation property, see Configure the Modbus Scanners Settings.
Real (Floating Point)
The value is formatted as an IEEE 32-bit single-precision floating point value. Each REAL comprises 2 Modbus registers (analog points only).
When the Scanner's Operation is set to 'Write' or 'Read/Write', this option is only available if the associated Modbus Slave Device's Write Holding Registers property is set to 'Multiple (Function Code 16)'. For information about configuring the latter property, see Configure Modbus Slave Device Configuration Settings. For information about configuring the Modbus Slave Scanner's Operation property, see Configure the Modbus Scanners Settings.
Enter the first address in the Modbus register range that you want scanned.
The valid range depends on the Modbus data type:
- 5-digit register address—1 to 9999 (Read, Write) or 10001 to 19999 (Read)
- 6-digit register address—1 to 65535 (Read, Write) or 100001 to 165535 (Read)
- 5-digit register address—30001 to 39999 (Read) or 40001 to 49999 (Read, Write)
- 6-digit register address—300001 to 365535 (Read, Write) or 400001 to 465535 (Read, Write)
Enter the total number of Modbus registers that are to be scanned and mapped. For example, DINT and REAL data types require twice as many Modbus Registers as UINT or INT data types.
Scan Rate
Enter the frequency rate at which the SCADAPack x70 device scans the point. Enter the rate directly in the field (see Specify a Time Period in the OPC Time Format) or use the Interval Window to specify the rate that you require.
To use the same scan rate as the Modbus Slave (see Configure Modbus Slave Device Configuration Settings), leave the default setting of 0.
Timeout
Use this check box to specify the amount of time that the SCADAPack x70 device should wait for a response when it scans the point on the Modbus Slave device. To use the same timeout as the Modbus Slave, leave the default setting of 0.
If the SCADAPack x70 device does not get a response in this time, it will try the scan again until it exceeds the Maximum Consecutive Timeouts count. If the SCADAPack x70 device still cannot get a response after the retries, it will determine that it cannot communicate with the device, (see Configure Modbus Slave Device Configuration Settings).
Enter the required interval in the OPC Time Format. You can enter the value directly in the field, or use the Interval window (accessed via the field's browse button) to specify the required value.
The timeout value that you enter is for each scan.
Further Information
Link SCADAPack x70 Analog, Digital, or Counter Configuration items to the relevant Modbus Point Scanner: see Configure the Properties on the Mapping Tab.