20
9.
9.9.
9. 
 
 Exchanged Data Structures
Exchanged Data StructuresExchanged Data Structures
Exchanged Data Structures 
 
 
9.1
9.19.1
9.1 
 
 Output (Control) Data Format
Output (Control) Data FormatOutput (Control) Data Format
Output (Control) Data Format 
 
 
The output data structure from the network master to the G3 Profibus interface card 
is comprised of 8 bytes structured as 4 words: 
 
 
Offset Data  Explanation 
0 
Command word 
high byte 
1 
Command word 
low byte 
Bit-level drive control command word (refer to  
Table 1 :  Command Word Format) 
2 
Frequency 
command high byte 
3 
Frequency 
command low byte 
Drive’s frequency command 
4 
Parameter number 
/ action high byte 
5 
Parameter number 
low byte 
Parameter action bits and upper 4 bits of the 
parameter register number.  Refer to section 10 
for a detailed explanation of this data word 
6 
Parameter data to 
write high byte 
7 
Parameter data to 
write low byte 
During parameter register writes, this word 
contains the data to write.  Refer to section 10 
for a detailed explanation of this data word 
 
 
The data contained in the frequency command word must be the desired frequency 
command multiplied by 100, and then converted to hexadecimal.  In other words, if a 
frequency command of 55.34Hz is desired, then 55.34 x 100 = 5534, which 
converted to hexadecimal is 0x159E.  The frequency command high byte (offset 2) 
must therefore contain 0x15, and the frequency command low byte (offset 3) must 
contain 0x9E. 
 
In this way, the G3’s allowable frequency command range of 0.00Hz ∼ 400.00Hz 
equates to network values of 0x0000 ∼ 0x9C40. 
 
Regardless of the frequency command value sent via the Profibus network to the 
drive, the actual operating frequency of the drive will still be limited locally by the 
LOWER LIMIT FREQUENCY, UPPER LIMIT FREQUENCY, and MAXIMUM OUTPUT
FREQUENCY parameter settings.