Schneider Electric PM850, PM870, PM820, PM810 manual Appendix C-Using the Command Interface

63230-500-225A2	PowerLogicTM Series 800 Power Meter
3/2011	Appendix C—Using the Command Interface

Appendix C—Using the Command Interface

Overview of the Command Interface

The power meter provides a command interface, which can be used to issue commands that perform various operations such as controlling relays. Table C–1 lists the definitions for the registers.Table C–2lists the available commands. The command interface is located in memory at registers 8000–8149.

Table C–1: Location of the command interface

Register	Description
8000	This is the register where you write the commands.
	These are the registers where you write the parameters for a
8001–8015	command. Commands can have up to 15 parameters associated with
	them.
8017	Command pointer. This register holds the register number where the
	most recently entered command is stored.
8018	Results pointer. This register holds the register number where the
	results of the most recently entered command are stored.
8019	I/O data pointer. Use this register to point to data buffer registers
	where you can send additional data or return data.
	These registers are for you (the user) to write information. Depending
	on which pointer places the information in the register, the register can
	contain status (from pointer 8017), results (from pointer 8018), or data
8020–8149	(from pointer 8019). The registers will contain information such as
	whether the function is enabled or disabled, set to fill and hold, start
	and stop times, logging intervals, and so forth.
	By default, return data will start at 8020 unless you specify otherwise.

When registers 8017 through 8019 are set to zero, no values are returned. When any or all of these registers contain a value, the value in the register “points” to a target register, which contains the status, error code, or I/O data (depending on the command) when the command is executed. Figure C–1shows how these registers work.

NOTE: You determine the register location where results will be written. Therefore, take care when assigning register values in the pointer registers; values may be corrupted when two commands use the same register.

Figure C–1: Command interface pointer registers

Register 8017

8020

Register 8018

Register 8019

	Register 8020	1	(status of the
			last command)
8021
			(error code caused by
	Register 8021	51
			the last command)
8022
			(data returned by the
	Register 8022	0
			last command)

Refer to “Register List Access” on page 79 for instructions on accessing the complete register list.

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