5.3  Registers
5.3.1  Types of Registers
5-36
( 2 ) Function Registers
The following table shows the registers that can be used with each function.
 n: Decimal number; h: Hexadecimal number
 B, W, L, F, and A: Data type (B: Bit, W: Integer, L: Double-length integer, F: Real number, A: Address. Refer to 5.3.2 
Data Types.)
 SA, MA, IA, OA, DA, #A, and CA registers can be used within functions.
Type Name Specification Method Range Details Characteristics
X
Function input regis-
ters
XB, XW, XL, XFnnnnn
XW00000 to 
XW00016
Input to functions
Bit input: XB000000 to XB00000F
Integer input: XW00001 to XW00016
Double-length integer input: XL00001 to 
XL00015
Unique to each 
function
Y
Function output reg-
isters
YB, YW, YL, YFnnnnn
YW00000 to 
YW00016
Output from functions
Bit output: YB000000 to YB00000F
Integer output: YW00001 to YW00016
Double-length integer output: YL00001 
to YL00015
Z
Internal function 
registers
ZB, ZW, ZL, ZFnnnnn
ZW00000 to 
ZW00063
Internal registers unique to each function 
Can be used for function internal process-
ing.
A
External function 
registers
AB, AW, AL, AFhhhhh
AW00000 to 
AW32767
External registers with the address input 
value as the base address. 
For linking with S, M, I, O, #, and 
DAnnnnn.
#
# registers
#B, #W, #L, #Fnnnnn 
(#Annnnn)
#W00000 to 
#W16383
Call-only registers 
Can be called only from the relevant func-
tion. The usage range is set by the user 
using MPE720.
D
D registers
DB, DW, DL, DFnnnnn 
(DAnnnnn)
DW00000 to 
DW16383
Internal registers unique to each function.
Can be called only the relevant function. 
The usage range is set by the user using 
MPE720.
S
System registers
SB, SW, SL, SFnnnnn 
(SAnnnnn)
Same as DWG registers
These registers are shared by drawings and functions. Pay attention to how these 
registers are to be used when calling the same function from a drawing of a dif-
ferent priority level. 
M
Data registers
MB, MW, ML,
MFnnnnn
(MAnnnnn)
I
Input registers
IB, IW, IL, IFhhhh 
(IAhhhh)
O
Output registers
OB, OW, OL, OFhhhh 
(OAhhhh)
C
Constants registers
CB, CW, CL, CFhhhh 
(CAnnnn)