Delta RMC151 - Manual (Page 422)

RMC70/150 and RMCTools User Manual
If you are connecting the HMI to the communications serial port on the RMC75S, make
sure you configure the RMC75S serial settings identically to the PLC communication
settings.
Using the Communications
Reading and Writing Registers
Read and write to registers in the RMC just as you would with a PLC. Some register
addresses are displayed in RMCTools, such as in the Axis Tools, Indirect Data Map, and
the Variable Table. To view those addresses in various formats, right-click the address
and choose Address Formats. To find other RMC addresses, use the Register Map.
The RMC contains only 32-bit registers. Most are floating-point registers, but some are
double integers (DINT) or double words (DWORD).
Issuing Commands
Issuing commands consists of writing to the command registers. The HMI must be able to
write to several registers at once. See the Issuing Commands topic for more details.
Viewing Individual Bits
Individual bits in the RMC can be used to view the state of the controller. For example,
the Halted bit indicates whether an axis is halted.
Most HMIs can read individual bits from the RMC if they use Modbus/TCP or
Modbus/RTU. With the Allen-Bradley CSP or DF1 protocols, viewing individual bits may
be difficult for some HMIs because the RMC registers can onlt be accessed as F or L
register types.
Tips on Using the RMC with an HMI as a Stand-alone System
For small machine applications, the RMC is fully capable of acting as a stand-alone system
together with an HMI. Several features in the RMC make this possible for many types of
systems:
• Start in RUN Mode
The RMC can be set to start in RUN mode. It is immediately ready for motion without
requiring the user to enable it from the HMI. See the Run/Program Mode topic for
details.
• Start a User Program on Startup
If the RMC is set to start up in RUN mode, it is possible to start a User Program
immediately. This is accomplished by using the _FirstScan bit in the Program Triggers.
See the Program Triggers topic for details.
• User Programs
User Programs can perform complex motion sequences and mathematical operations.
See the User Programs topic for details.
• Program Triggers
The Program Triggers allow the RMC to respond to discrete inputs to any other
condition, without requiring that the user explicitly command it to do something. See
the Program Triggers topic for details.
Sample Programs
Delta's website provides sample HMI programs for communicating with the RMC. These
programs demonstrate reading and writing registers and issuing commands. Using the
demo programs can drastically reduce your development time.
The sample programs are available from the downloads page.
6.6. Discrete I/O for Communications
402 Delta Computer Systems, Inc.