Hitachi NJI-350B manual Memory Size and Memory Assignment, Sram, Flash

7-1

Chapter 7 Programming

Chapter 7 Programming

7.1 Memory Size and Memory Assignment

Table 7.1. Lists the programming specifications for the MICRO-EH.

Table 7.1 Programming specifications

No.		Item		10/14-point type	23/28-point type
1		Program size		3 k steps (3072 steps)
2		Instruction size		32 bits/1 step
3		Memory specification	SRAM	Backup with a battery is not possible	Backup is possible by installing the
				since a battery cannot be installed.	battery.
			FLASH	Backup using flash memory is possible.
4		Programming language		H-series ladder/instruction language
5		Program creation		Created with H-series programming devices
6		Program modification	During STOP	Can be done as desired from the programming devices.
			During RUN	Can be done using the modify during RUN operation (except control instructions).
				Control instructions can be changed with special operations. *1
				(When a change is made during RUN, control operation stops while the program
				is being modified.).
7		Program protection		Programs can only be modified when write is enabled. (The enable status is
				automatically controlled by the programming device).
8		Password		A password can be set from the programming device (the program cannot be
				displayed when setting the password. The programs can be downloaded to the
				programming device).
9		Check function		A sum check function for the program is always executing. An address check with
				the I/O assignment table is executed when RUN operation starts.
10		Program name		The program names are set from the programming device and stored along with
				the programs.
*1:	Refer to the peripheral unit manual for details.
Notes:

•Comment data that has been created with the peripheral unit is not stored in the CPU.

•Save the user programs to a floppy disk or other media for backup.

•If a program exceeding 3072 steps is created by setting 4 K steps in the LADDER EDITOR, no error occurs in the LADDER EDITOR, but a “writing outside memory range” error will occur when writing the program to the CPU.

•Unlike the conventional H series, the MICRO-EH series backup user programs in the FLASH memory.

In order to shorten the program transfer time, the user programs are transferred once to the operation execution memory, at which point the transfer is completed. The backup to the FLASH memory is performed afterward; therefore, be sure to turn off the power to the main unit after approximately two minutes have passed since the program transfer. If the power is turned off within two minutes, a user memory error (31H) may occur. Note that the transfer completion to the FLASH memory can be confirmed by the special internal output (R7EF).