Omron Sysmac CS1 Operation Manual page 90

Details
6-2-8 EM Area
Address Bits
DM 6600 12 to 15 Hold function for EM Area
(EM 0000 to EM 2047)
70
Note Writing is not possible when bits 00 to 03 in DM 6600 are set to 1 Hex (writing to
user memory disabled). (Except for bits 00 to 03 in DM 6600.)
This area is used in word units (EM 0000 to EM 2047). The EM Area is contained
in I/O memory (i.e., memory that can be freely read and written to from the ladder
program). It is possible to specify whether or not EM Area settings are cleared at
power interruptions. This setting is made in bits 12 to 15 of DM 6600 in the Unit
Setup Area as shown below.
Function Contents
0 Hex: Cleared
1 Hex: Held
Note: Set to 0 Hex to clear the EM Area and
subsequently reduce the execution time for
instructions that access (i.e., read/write) this
area.
Section 6-2