|
<< Click to Display Table of Contents >>
[N/B] Parameters for PLC or Block Tags |
N1/B1 |
Slave ID, between 1 (one) and 247 |
N2/B2 |
PLC Tag's data type. For more information, please check table Available data types |
N3/B3 |
String length, if the N2/B2 parameter is equal to 7 (seven) |
N4/B4 |
Address of the variable of local Modbus registers, between 0 (zero) and 65535 |
N2/B2 |
Data Type |
Size |
Modbus Registers |
|---|---|---|---|
1 |
Bit (bit register) |
One byte |
Occupies one bit of a Modbus register |
2 |
Word (16-bit unsigned integer) |
Two bytes |
Occupies one Modbus register |
3 |
Short (16-bit signed integer) |
Two bytes |
Occupies one Modbus register |
4 |
Double Word (32-bit unsigned integer) |
Four bytes |
Occupies two Modbus registers |
5 |
Int (32-bit signed integer) |
Four bytes |
Occupies two Modbus registers |
6 |
Float (32-bit floating point, EXP F0 F1 F2) |
Four bytes |
Occupies two Modbus registers |
7 |
String (text) |
N bytes |
Two characters per Modbus register |
8 |
Reverse Float (F2 F1 F0 EXP) |
Four bytes |
Occupies two Modbus registers |
9 |
Double (64-bit floating point, EXP F0 F1 F2 F3 F4 F5 F6) |
Eight bytes |
Occupies four Modbus registers |
10 |
Reverse Double (64-bit floating point, F6 F5 F4 F3 F2 F1 F0 EXP) |
Eight bytes |
Occupies four Modbus registers |
NOTE |
For String data types, the maximum allowed size in N3/B3 is 250 characters for a PLC Tag. For a Block Tag, on the other hand, the maximum size of 250 characters allowed must be divided by the number of Elements in the Block Tag. For example, for a Block Tag with 10 Elements, the maximum allowed size in N3/B3 is 25 characters. |