Data Registers (D) - Delta AS Series Programming Manual

AS Ser ies Pro gra mm in g M anu al

2.2.13 Data Registers (D)

The data register stores 16-bit data. The highest bit represents either a positive sign or a negative sign, and the values
that the data registers can store range between -32,768 to +32,767.
Two 16-bit registers can be combined into a 32-bit register; for example, (D+1, D) in which the lower number register
represents the low 16 bits. The highest bit represents either a positive sign or a negative sign, and the values that the
_2 data registers can store range between -2,147,483,648 to +2,147,483,647.

Four 16-bit registers can be combined into a 64-bit register; for example, (D+3, D+2, D+1, D) in which the lower
number register represents the lower 16 bits. The highest bit represents either a positive sign or a negative sign,
and the values that the data registers can store range between -9,223,372,036,854,776 to
+9,223,372,036,854,775,807.

You can also use the data registers to refresh the values in the control registers in the modules other than digital
I/O modules. Refer to the ISPSoft User Manual for more information on refreshing the values in the control
registers.
There are three types of registers.

General-purpose registers: When the PLC changes to RUN, or is disconnected, the value in the register is cleared
to zero. If you want to retain the data when the PLC changes to RUN, Refer to the ISPSoft User Manual for more
information. Note that the value is still cleared to zero when the PLC is disconnected.

Latched register: If the PLC is disconnected, the data in the latched register is not cleared. In other words, the
value before the disconnection is retained. If you want to clear the data in the latched area, you can use the RST or
ZRST instructions.

Frequently mapped registers: If the PLC program contains a module, after each scan cycle, the PLC performs data
mapping with the module. And the mapped data is stored between D26000~D29999. Refer to Chapter 8 of AS
Operation Manual for more details on the automatically assigned addresses of the devices. You can also check the
assigned addresses of the device while configuring in HWCONFIG of ISPSoft.
2 - 8 0