Rockwell Automation 57C411 Resolver Input Module - Manual (Page 19)

4Ć1
4.0 PROGRAMMING
This section describes how the data is organized in the module and
provides examples of how the module is accessed by the application
software. For more detailed information refer to the DCS 5000
Enhanced BASIC Language Instruction Manual (JĆ3600).
4.1 Register Organization
The input module contains a total of five 16Ćbit registers. Registers 0
and 1 contain resolver position data. The resolverĆtoĆdigital converter
provides 12 bits of resolution. Register 0 is updated with new position
information at the rate specified in register 4. Register 1 is updated
whenever the EXTERNAL STROBE goes from false to true. These
registers are read only. Refer to figure 4.1.
register 0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
0 0
register 1 0 0
resolver data
resolver external latch data
electronic revolution counter
bits
Figure 4.1 Ć Resolver Data Registers
Registers 2 and 3 are the interrupt status and control registers. Both
registers contain the same information. Register 2 is read only.
Register 3 is read/write. If the module is located in a remote rack, you
must read the status from register 2. With the exception of bit 6 and
bit 12, this register is controlled by the operating system and must
not be manipulated by the user. Refer to figure 4.2.
For this module to operate properly, the common clock signal must
be present on the backplane. The common clock signal is a 4 mhz
clock that can be connected to all the I/O modules in the rack. It can
be generated from a number of DCS 5000 I/O modules. If this
module is to drive the common clock, bit 6 must be set.