Schneider Electric PM870 Marine Instruments User Manual


 
© 2011 Schneider Electric. All Rights Reserved.
63230-500-225A2 PowerLogic
TM
Series 800 Power Meter
3/2011 Appendix C—Using the Command Interface
87
Using the Command Interface to Change Configuration Registers
You can also use the command interface to change values in selected metering-related
registers, such as setting the time of day of the clock or resetting generic demand.
Two commands, 9020 and 9021, work together as part of the command interface
procedure when you use it to change power meter configuration. You must first issue
command 9020 to enter into setup mode, change the register, and then issue 9021 to save
your changes and exit setup mode.
Only one setup session is allowed at a time. While in this mode, if the power meter detects
more than two minutes of inactivity, that is, if you do not write any register values or press
any buttons on the display, the power meter will time out and restore the original
configuration values. All changes will be lost. Also, if the power meter loses power or
communications while in setup mode, your changes will be lost.
The general procedure for changing configuration registers using the command interface is
as follows:
1. Issue command 9020 in register 8000 to enter into setup mode.
2. Make changes to the appropriate register by writing the new value to that register.
Perform register writes to all registers that you want to change. For instructions on
reading and writing registers, see “Read and Write Registers” on page 26.
3. To save the changes, write the value 1 to register 8001.
NOTE: Writing any other value except 1 to register 8001 lets you exit setup mode
without saving your changes.
4. Issue command 9021 in register 8000 to initiate the save and reset the power meter.
For example, the procedure to change the demand interval for current is as follows:
1. Issue command code 9020 in register 8000.
2. Write the new demand interval to register 1801.
3. Write 1 to register 8001.
4. Issue command code 9021 in register 8000.
Refer to “Register List Access” on page 79 for instructions on accessing the complete
register list.
Conditional Energy
Power meter registers 1728–1744 are conditional energy registers.
Conditional energy can be controlled in one of two ways:
Over the communications link, by writing commands to the power meter’s command
interface, or
By a digital input—for example, conditional energy accumulates when the assigned
digital input is on, but does not accumulate when the digital input is off.
The following procedures explain how to set up conditional energy for command interface
control and for digital input control. The procedures refer to register numbers and command
codes. For a listing of command codes, see Table C–2 on page 84.