Programmer (HHP) User guide

Reference
Appendix B
Programming Reference
B–12
Address
Bit Classification Description
S16H
➀
DH-485 Baud
Rate
Status This byte value contains the baud rate of the processor on the
DH-485 link.
The controller baud rate options are:
• 9600
• 19200 (default)
To change the baud rate from the default value, you must use a
programming device.
S17 to S21 Reserved NA NA
S22 Maximum
Observed Scan
ie
Dynamic
Configuration
This word indicates the maximum observed interval between
consecutive program cycles.
bser e ca
Time
fi ra i
This value indicates, in 10 ms increments, the time elapsed in
the longest program cycle of the controller. Refer to S:3L for
more information regarding the program cycle. The controller
compares each last scan value to the value contained in S:22.
If the controller determines that the last scan value is larger
than the value stored at S:22, the last scan value is written to
S:22.
Resolution of the maximum observed scan time value is +0 to
−10 ms. For example, the value 9 indicates that 80–90 ms was
observed as the longest program cycle.
Interrogate this value if you need to determine or verify the
longest scan time of your program.
S23 Reserved NA NA
S24 Index Register Status
This word indicates the element offset used in indexed
addressing.
When an STI, high-speed counter, or Fault Routine interrupts
normal execution of your program, the original value of this
register is restored when execution resumes.
S25 to S29 Reserved NA NA
S30
➀
STI Setpoint Dynamic
Configuration
You enter the timebase to be used in the selectable timed
interrupt (STI). The time can range from 10 to 2550 ms. (This is
in 10ms increments, so valid values are from 0–255.) Your STI
routine executes per the value you enter. Write a zero value to
disable the STI.
To provide protection from inadvertent alteration of your
selection, program an unconditional MOV instruction containing
the setpoint value of your STI to S:30, or program a CLR
instruction at S:30 to prevent STI operation.
If the STI is initiated while in the REM Run mode by loading the
status registers, the interrupt starts timing from the end of the
program scan in which the status registers were loaded.
S31 to S32 Reserved NA NA
➀
Address is not shown in HHP data monitor.