B&B Electronics MODSCAN32 - Manual - Manual (Page 78)

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Data may be accessed from the control via the following array properties:
Coil()
This array property allows the control application to read or write a boolean
value from/to the slave device. A read operation does not verify proper data
addressing of the point prior to returning the value. If the control property data
address has been configured to scan register values from the MODBUS device,
erroneous readings will occur if the Coil property is used to access the data
array. Likewise, if the property is used to update a Coil using a control
configured to read registers, no write command will be issued to the MODBUS.
Register() This array property allows the control application to read or write 16-bit integer
values from/to the slave device. A read operation does not verify proper data
addressing of the point prior to returning the value. If the control property data
address has been configured to scan coil values from the MODBUS device,
erroneous readings will occur if the Register property is used to access the data
array. Likewise, if the property is used to update a Register using a control
configured to read coils, no write command will be issued to the MODBUS.
Float() This array property allows the control application to read or write floating-point
values from/to the slave device. A floating-point value requires 32 bits and is
stored in supporting slave devices as two consecutively addressed registers.
MODBUS command 03 or 04, (Register Reads), are used by the control to
access the data and each control is capable of scanning up to 64 floating-point
values. Some devices may store the value with the high-order bits in the first
register and the low order bits in the second register. Other slave devices may
invert the word-order. Valid floating point values may only be obtained from a
control configured to scan registers. Attempting to read or write a floating-point
value to a control which has been configured to scan Coils will result in
erroneous readings.
Indexing used to access Floating point values is zero-based, times 2, (the index
reflects the starting register location for the floating-point value—NOT the
index of the 32-bit value contained in the array). Each floating point value
requires two consecutive registers, therefore accessing Float(0) returns the value
contained in Register(0) and Register(1). Accessing Float(8) returns the fifth
floating-point value in the array, (contained in Register(8) & Register(9)).
WSFloat() Read or Write a Word-Swapped floating point value.