Siemens s7 & Danfoss, PPO 1

Hi
I have inherited a project where the 2 danfoss drives (FC300 in the S7 hardware config) are connected via profibus, using PPO1 to a Siemens S7 master.

For drive #1 the address in the PLC for word consistent PCD feedback is PIW256-263 and for drive #2 is PIW268-275

The drives run reasonably OK but I cannot get the MAV (Drive actual speed figure into the PLC. The only value that seems to change as the drives work is PIW266. PIW 264 has a static value in it which I assume is the running status.

These don't seem to tally with the danfoss manual.

As an example I had W#16#0AD3 (2771 decimal) in PIW266 when drive #1 was running at about 39% speed

The min/max is set to 600 rpm min and 2900 rpm max so was wondering if that was skewing the data

Any help gratefully received

Cheers

cjd1965 said:

Hi
I have inherited a project where the 2 danfoss drives (FC300 in the S7 hardware config) are connected via profibus, using PPO1 to a Siemens S7 master.

For drive #1 the address in the PLC for word consistent PCD feedback is PIW256-263 and for drive #2 is PIW268-275

The drives run reasonably OK but I cannot get the MAV (Drive actual speed figure into the PLC. The only value that seems to change as the drives work is PIW266. PIW 264 has a static value in it which I assume is the running status.

These don't seem to tally with the danfoss manual.

As an example I had W#16#0AD3 (2771 decimal) in PIW266 when drive #1 was running at about 39% speed

The min/max is set to 600 rpm min and 2900 rpm max so was wondering if that was skewing the data

Any help gratefully received

Cheers

Click to expand...

The addresses you are monitoring (in red) are not inside the address range of the drives (bold black).

Hi I was aware of that but all the PIW addresses remain at 0.... so I assume it is a problem with the drive settings or the PLC is not requesting the data

PPO1 for the Danfoss FC300 drives consist of:

12 bytes total.
First 8 byte are used to read/change parameters.
Last 4 bytes are used for Status/Control-words (byte 9-10) and Reference/Actual speed value (byte 11-12)

Although all 12 bytes should be read/written consistently, the first 8 are used situational, means they will be configured separately.
The last 4 can be read/written as simple PID/PQD.

As you said, PIW 264 is stable, this is indeed the statusword.
PIW266 should be the Actual Speed value.
Note on the speed value: It's a representation of the current value relative to the configured min/max.
To put it in other words, at the min speed you'll read 0. At the max speed you'll read 16384 (4000 in hex).
Danfoss uses 0 - 4000 hex to display 0 - 100%.



This reminds me of a few days of sighing, getting frustrated, etc, trying to find the correct manuals.

Use google to look for following manuals:
MG.90.A5.02 - Overview of Profibus comms, PPO types and on one page it mentions the 0 - 4000 hex range, it's easy to miss.
MG.90.E1.02 - In depth explanation of the Profibus DP V1 comms.

Confusing

The hardware shows 4AX = PIW256-263 and 113 = PIW264-267

I have values showing in PIW263-267

PIW 266 shows 0A7E which is 16.4% calculated. Drive shows 33.7% on the op panel.

Min Speed is set to 600 rpm for some reason, it is a process water circulation loop.

600 RPM is about 26% of the operating range of 600-2900rpm so is this skewing the figure and I can see how to add this offset because 2900 rpm would be 100% speed without an offset

4-20mA hard wired is so much easier

Cheers

Hardware is configured as PPO type 1 Word Consistent PCD.
As discribed in previous post, the 4AX is used to read/write parameters.
This is used on command. (scanned when needed)
The 113 is Command + Status words and Reference/Actual value.
This is read/written continouosly.

As the manual stated, the read out is a 0-100% (0-4000hex) representation.
100% being the value in parameter 202. 0% being....well 0. (got this wrong in previous post, just double checked in our systems)

Siemens s7 & Danfoss, PPO 1 with PIW264-275 ?

Hi
I have inherited a project where the 2 danfoss drives (FC300 in the S7 hardware config) are connected via profibus, using PPO1 to a Siemens S7 master.

For drive #1 the address in the PLC for word consistent is PIW256-263 The drives#1 run reasonably OK
For drive #2 the address in the PLC for word consistent is PIW264-275
but i cant make communication for drive #2.

How I can Adjust the drives (FC300 ) for synch to PIW264-275


Any help gratefully received

saeed

cjd1965 said:

Hi
I have inherited a project where the 2 danfoss drives (FC300 in the S7 hardware config) are connected via profibus, using PPO1 to a Siemens S7 master.

For drive #1 the address in the PLC for word consistent PCD feedback is PIW256-263 and for drive #2 is PIW268-275

The drives run reasonably OK but I cannot get the MAV (Drive actual speed figure into the PLC. The only value that seems to change as the drives work is PIW266. PIW 264 has a static value in it which I assume is the running status.

These don't seem to tally with the danfoss manual.

As an example I had W#16#0AD3 (2771 decimal) in PIW266 when drive #1 was running at about 39% speed

The min/max is set to 600 rpm min and 2900 rpm max so was wondering if that was skewing the data

Any help gratefully received

Cheers

Click to expand...

Hi
I have inherited a project where the 2 danfoss drives (FC300 in the S7 hardware config) are connected via profibus, using PPO1 to a Siemens S7 master.

For drive #1 the address in the PLC for word consistent is PIW256-263 The drives#1 run reasonably OK
For drive #2 the address in the PLC for word consistent is PIW264-275
but i cant make communication for drive #2.

How I can Adjust the drives (FC300 ) for synch to PIW264-275


Any help gratefully received

saeed