6. Function blocks
6.1 Manufacturer function blocks
Function block outputs
 Description Note
(bit) 
RY
1: Request sent and positive response
received from slave.
0: Request sent, but Modbus exceptions
received as response from slave.

BY
BUSY
1: Waiting for slave response.
0: The request has been completed.

E1
ERROR
1: In the event of a rejection by the slave or a
formal error.

(DWord)
QV
Actual number of elements
Integer value range:
FC1, FC2, FC5, FC15: 0…+2000
FC3, FC4, FC6, FC16, FC23: 0…+125
QN
Only relevant to function code FC23:
Actual number of elements for 2nd request
Integer value range:
0…+125
EC
Fault Code
Assigning operands
You can assign the following operands to the function block outputs that are numeric
outputs:
Assigning operands Value outputs
MB, MD, MW – Markers
x
NB, NW, ND – NET markers
2)
NET station n
x
QA – Analog output
x
I – Value input of a FB
x
2)
Only on projects with ≥ 2 base devices on NET 
You can assign the following operands to the function block outputs that are bit out-
puts:
Assigning operands Bit outputs
M - Markers
x
SN – Output bit via NET (send)
2)
SN - Output
bit via NET (send)
x
N – Network marker bit
2)
x
LE – Output backlight
x
Q – Bit output
x
I – Bit input of a FB
x
2)
Only on projects with ≥ 2 base devices on NET 
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