Hi to all,

i need a help from you. I have two Flying saw system with 1500T CPU and one absolute encoder profinet. 

I generate TO_encoder_1 for the first flyingsaw and TO_encoder_2 for the second one. The first Flying saw work making some holes in the material and the second one with a photocell detect the hole and make a cut on the material.

1) If i use the same encoder with two TO_Encoder, can i have some problems? 

2) Is there any problems with the overflow of the encoder?

3) Can i reset the count of the TO_encoder_1 without influencing the count of TO_Encoder2?

The solution could be to have another encoder but the machine is made in this way unfortunaly…

Many thanks to all.

1. The TO_ExternalEncoder must interconnect with an exclusive IO interface, you cannot connect the same encoder with two TO_ExternalEncoder (project compiling finished with errors). Instead, you can connect the second TO_ExternalEncoder to "Data block": TO_ExternalEncoder > Hardware interface > Encoder > Data connection > "Data block", and update it's actual position from the Encoder telegram actual value in MC-PreServo OB, using Move instruction.
2. For Flying Saw application, normally reset TO_ExternalEncoder actual position after every cutting, so TO_ExternalEncoder won't overflow at all.
3. Two TO_ExternalEncoder have different data connections, so reset one TO_ExternalEncoder won't influence another one.

HI,

thanks for the answer..

If i follow your idea to use the move instruction in the MC_PreServo, if i preset the TO_ExternalEncoder every cut then the actual position is overwriten from the MC_PreServo.. so the preset of the actual position doesn't work..

Are you agree with me? 

Yes... but...
If the production line is unidirectional and nonstop, the TO_ExternalEncoder will overflow soon or later once reached the maximum value range of LREAL data type: -1.7976931348623157e+308 to -2.2250738585072014e-308; big enough and may never overflow at all in practice.
Overflow is not an issue to be considered first, the LREAL data type is processed with a precision of 15 digits, you will lose the precision along with the value increment.  
We normally reset the TO_ExternalEncoder after every cut, just like this application example:
SIMATIC S7-1500T Flying Saw (you may have already read).
Best regards,
Yu-Wen 

OK, many thanks for the information, i will give to you some feedbacks.

Thanks a lot

Hi, 

I didn't analized this solution but can be a possibility. Many thanks for your answer.. Next days i start up the machine and i try.

Many thanks again.

HI,

do you have the link for download the flying saw advanced program example?

Many thanks