Stanley QB Expert, Инструкция по эксплуатации

Страница: 134 / 214

Assignable Input and Output Functions
QB Expert Alpha Controller
126
Outputs: Sinking
(example)
6.12 Assignable Input and Output Functions
The following Input/ Output (I/O) functions apply to the 24V DC I/O connector. There is a maximum of eight
inputs and eight outputs for the 24V DC I/O connector. There is a maximum of 512 bytes of input and 512 bytes
of output on each type of Fieldbus used with the controller (except DeviceNet with a limit of 256 bytes for both
inputs and outputs). Ninety-nine is the maximum number of I/O functions that can be assigned to each Fieldbus
input or output. Each I/O function can have a length of 1 to 32 bits. You must keep track of the lengths for each
I/O function you assign to stay within the maximum length of the Fieldbus you are using.
More than one Fieldbus connection can be used at the same time. For instance, the Alpha controller can use the
24V DC I/O connector AND ModbusTCP on Ethernet AND DeviceNet all at the same time. If more than one type
of Input uses a particular function, the controller responds to an input when a function is asserted on any one of
those inputs.
It is important to understand how the Alpha controller, and the internal PLC, responds to the rising and falling
edges of input functions as they are asserted or removed, not while the levels are high or low. The STOP bit is an
exception; it is a true OR function rather than working off the transition. One type of Input does not have priority
over the other. The controller responds to the first change in status of an input function, no matter which Fieldbus
connection makes the change.
If more than one Fieldbus shares a particular output function, that function is asserted on all shared fieldbuses.
The table below lists the available input and output functions, gives a brief description and indicates the
configuration options for each. The configuration options are an important aspect of the I/O functions, as they
add powerful, multiple dimensions to each function in the controller. These new dimensions allow integration of
the controller in unique ways, providing increased flexibility.