7.1.12 Write a parameter via the ASCII channel
The KP value for the current controller is to be set through the ASCII channel. The command is
then MLGQ_1.985. Here the understroke stands for a space. Since every telegram only has 10
positions available for the transmission of ASCII characters, the termination of the line (“CR LF”)
must be transmitted in a second telegram.
Conditions:
ASCII mode is switched on (PNU 930 = -16)
Bit 13 STW = 0 (if necessary, toggle Bit 14 STW until Bit 13 ZSW = 0)
Procedure:
1. Write data to PZD 2..6 and invert Bit 12 STW
Byte 1 2 3 4 5 6
0001 0000 0000 0000 0100 1101 0100 1100 0100 0111 0101 0001
PZD1 PZD2 PZD3
STW “M” “L” “G” “Q”
Byte 7 8 9 10 11 12
0010 0000 0011 0001 0010 1110 0011 1001 0011 1000 0011 0101
PZD4 PZD5 PZD6
“_” “1” “.” “9” “8” “5”
2. Wait for the transition edge on Bit 12 ZSW
3. Continue writing data to PZD 2...6 and invert Bit 12 STW
Byte 1 2 3 4 5...12
0000 0000 0000 0000 0000 1101 0000 1010 0000 0000
PZD1 PZD2 PZD3..6
STW “CR” “LF”
4. Wait for the transition edge on Bit 12 ZSW
5. Wait until Bit 13 ZSW = 1
6. Invert Bit 14 STW
7. Wait until Bit 14 ZSW = 1
8. The servo amplifier sends a response telegram
Byte 1 2 3 4 5 6
0110 0010 0000 0000 0100 1101 0100 1100 0100 0111 0101 0001
PZD1 PZD2 PZD3
ZSW “M” “L” “G” “Q”
Byte 7 8 9 10 11 12
0010 0000 0011 0001 0010 1110 0011 1001 0011 1000 0011 0101
PZD4 PZD5 PZD6
“_” “1” “.” “9” “8” “5”
9. Repeat steps 5 to 8 until a response telegram indicates “EOT”.
Byte 1 2 3 4 5 6 7...12
0000 0010 0000 0000 0000 1101 0000 1010 0000 0100 0000 0000 0000 0000
PZD1 PZD2 PZD3 PZD4..6
ZSW “CR” “LF” “EOT”
Note: The sequence of response telegrams shown above is only one of many possibilities (for the
same response from the servo amplifier). Because of the transmission rate and the internal syn-
chronization mechanism, it can happen that process data sections remain empty and so the
response is broken into segments. This could possibly alter the number of response telegrams.
S300-S400-S600-S700 PROFIBUS | 7 Appendix
Kollmorgen | kdn.kollmorgen.com | December 2019 51