Control Techniques Epsilon EP-P, Справочное руководство

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Epsilon EP-P Drive Reference Manual
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www.controltechniques.com Revision: A4
Figure 81: User Bits View
3.24.1 Adding and Deleting User Bits
Bits can be added or deleted in groups of 32-bits. Individual bits cannot be added or deleted. The default number of User Bits available is 32.
To add an additional 32 bits, simply click on the up arrow next to the “Number of Bit Registers” box at the top of the User Bits view (see Figure
81).
To decrease the number of User Bits by 32, click on the down arrow next to the “Number of Bit Registers” box. When decreasing the number of
User Bits, it is always the last 32 bits in the list that will be eliminated.
3.24.2 User 32-bit Bit Register and User Bit Masking
When using different communications protocols (i.e. DeviceNet, Profibus, Modbus), it is often desirable to access groups of User Bits in a
single parameter, rather than having to access them individually. In the Epsilon EP-P drive it is possible to access 32 User Bits in a single
parameter. This parameter is named BitRegister.#.Value. Because some of the 32 User Bits may be used by the program, and should not be
modified from the network communications, it is possible to “Mask Off” certain bits. Masking bits prevents them from being modified in the
program when the 32-bit parameter is written to.
When a User Bit Register (group of 32 User Bits) is written to, the value is then logic-AND’ed with the mask to determine the resulting state of
each of the 32 individual bits. If the individual bit value of the 32-bit mask is “1”, then the corresponding bit from the written 32-bit parameter is
passed through, and the resulting value stored in the specific bit will be the written bit value. If the bit value of the 32-bit mask is “0”, then that
particular bit is blocked (or masked), and the resulting bit value does not change, (Original Value AND NOT 32-Bit Mask) or (Value Written over
Network AND 32-Bit Mask). An example of this is shown in Figure 82.