FREAD

FREAD instruction copies a specified system memory of the special module and saves the result in the Destination.

(It supports only in CM1-PS02A special module)


n1	Slot number of special module
n2	Starting system memory to be read
D	Destination
n3	Number of system memory to be read
n4	Result of operation

Instruction

Device address

No. of Steps

Flag

M

X

Y

K

L

F

T

C

S

Z

D

@D

Int.

Error

Zero

Carry

FREAD

n1

o

-

o

6

o

-

n2

o

-

o

D

o

-

o

-

o

-

n3

o

-

o

n4

o

-

o

-

o

-

When enabled, the FREAD copies specified number(n3) of system memory(n2) from the special module(n1: slot number of expansion module) to the Destination (D device address) and saves the result of instruction operation in the n4.

n1 : HEX that shows Base and Slot number of expansion module.

Ex) H + (Base number) + (Slot number)

Base number	Slot number	n1
Local Base	Slot number 5.	H0005
Expansion Base number 1.	Slot number 3.	H0103
Expansion Base number 10.	Slot number 7.	H0A07
Expansion Base number 14.	Slot number 12.	H0E0C
Expansion Base number 16.	Slot number 10.	H100A

Please refer to below the Base and Slot number system for CM1 series.

n2 : Offset that is starting address of system memory to be read.

(Please refer to System memory of positioning module)

n3 : Size (number of system memory to be read)

The range of n3 is from 0 to 32,767.

If n3 is 0, instruction will not work and if n3 is out of range, it occurs an error.

n4 : the result of instruction operation is stored in n4.

Bit No.	Description
0	If instruction is running (1), If instruction is completed (0)
1	Error
2 – 7	Not used
8 - 15	Error Code 00H : No error 01H : Maximum 32 data can be read and write at the same time for a scan 02H : Data size is out of range 03H : Wrong Offset

The error flag is turned ON if :

a. CPU cannot access expansion module.

b. n1 is not special module (CM1-PS02A)

c. n3 exceeds Destination.

d. n3 is out of range (0 – 32,767)

Base and Slot number for CM1

Example)

If M00 is ON, the FREAD instruction copies 5words of system memory 29 from positioning module that is installed at slot no. 1 in the local base and saves its value to D0~D4 in sequence. The result of operation is stored in M00.