DF1 OPC Items

Standard Items

See Device Standard Items.

1774-PLC/PLC-2 Protocol Items

Item	Date Type	Description

Item	Date Type	Description
I:0	I4
N:0	I4
O:0	I4

PLC-5 Protocol Items

Item	Date Type	Description

Item	Date Type	Description
A10:0	String
B3:0	I4
BT13:0
C5:0
D14:0
F8:0	R4
I:0	I4
MG12:0
N7:0	I4
O:0	I4
PD11:0
R6:0
S:0	I4
SC15:0
ST9:0	String
T4:0

MicroLogix® 1000/SLC-500 Protocol Items

Item	Date Type	Description

Item	Date Type	Description
B3:0	I4
C5:0
I:0	I4
N7:0	I4
O:0	I4
R6:0
S:0	I4
T4:0

SLC-5/03/04/05/MicroLogix® 1200/MicroLogix® 1500 Protocol Items

Item	Date Type	Description

Item	Date Type	Description
A10:0	String
B3:0	I4
C5:0
F8:0	R4
I:0	I4
L9:0
N7:0	I4
O:0	I4
R6:0
S:0	I4
ST9:0	String
T4:0

Item Conversion

The DF1/ABTCP protocol module supports the following conversion flags to convert the register data in the device to another type in the client application.

Note

DF1 devices typically use 16-bit “N” (integer) registers, but ControlLogix® devices also support 32-bit registers.

Flag	Description

Flag	Description
/	Append a '/' to the register or status items followed by a bit number (starting at zero (0)) to access a single bit of a multi-bit data type. For example, N7:3/3 would access the third bit of N7:3.
.	A bit-width can be specified by appending a '.' followed by a number after the bit number specifier ('/'). For example, N7:3/3.2 would access the third and fourth bits of N7:3 and return them as an integer.
!	Append an ‘!’ to a Boolean to invert the value. For example, N7:3/3! would access the third bit of N7:3 and invert the value.
I	Append an 'I' to the register to access the data as a single, unsigned 16-bit integer value. For example, N7:3I would access the first 2 bytes at N7:3 and return it as an unsigned 16-bit integer - even if the register is native 32-bit.
IS	Append an ‘IS’ to the register to access the data as a single, signed 16-bit integer value. For example, N7:3I would access the first 2 bytes at N7:3 and return it as a signed 16-bit integer - even if the register is native 32-bit.
L	Append an ‘L’ to the register to access the data as a single unsigned, 32-bit integer value. For example, N7:3L would access the first 4 bytes beginning at N7:3 and return it as an unsigned 32-bit integer. If the register is native 16-bit, ACM will request both N7:3 & N7:4 and combine the result into a single value.
LS	Append an ‘LS’ to the register to access the data as a single signed, 32-bit integer value. For example, N7:3L would access the first 4 bytes beginning at N7:3 and return it as a signed 32-bit integer. If the register is native 16-bit, it will return N7:3 & N7:4 as a single value.
F	Append an ‘F’ to the register to access the data as a single 32-bit floating point value. For example, N7:3F would access 4 bytes beginning at N7:3 and return it as a 32-bit floating point value. If the register is native 16-bit, it will return N7:3 & N7:4 as a single value.
()	Append a number in parentheses to override the native data type length in bytes. This was done for newer series PLCs that can be configured to emulate older device types and support the DF1 protocol. For example, N7:2(4) tells ACM that N7:2 is a native 4 byte (32-bit) register. ACM will request one register and expect 4 data bytes.
^	Append a '^' and a byte order code number to the register to apply a specific byte order to the incoming and outgoing values. For example, N7:10F^3 reads the 4 bytes starting at N7:10, changes the word order, and interprets the result as a floating point value. If the registers are native 16-bit, it will use N7:10 & N7:11 as a single value. See the byte order code numbers table below.

Byte Order Code Numbers

Code Number	Message Bytes	Assembled Order	Notes

Code Number	Message Bytes	Assembled Order	Notes
1	1234	1234	No Change
2	1234	2143	Change byte order
3	1234	3412	Change word order
4	1234	4321	Change both