Host Engineering Forum

General Category => Do-more CPUs and Do-more Designer Software => Topic started by: davidbgtx on October 29, 2019, 05:53:37 AM

Title: Peerlink VS Ethernet
Post by: davidbgtx on October 29, 2019, 05:53:37 AM

What are the advantages of using Peerlink if it still communicating over ethernet, and if I understand slower. Is it just to avoid Modbus?

Title: Re: Peerlink VS Ethernet
Post by: BobO on October 29, 2019, 07:31:07 AM

Simplicity.

Title: Re: Peerlink VS Ethernet
Post by: franji1 on October 29, 2019, 07:31:34 AM

Ease of use.  PEERLINK just works.  You can easily share data across up to 16 Do-more PLCs with each other and an unlimited number of listeners/subscribers.

No configuration.  No addresses to set up.  Well defined blocks of shared data.  Only one PLC can publish the global Peerlink block 0.  Only one can publish block 1.  Etc.  It just works.

Try sharing data across just 2 or 3 PLCs using MRX/MWX or RX/WX.  It is not as easy as PEERLINK.  Much harder with 5 or 10.  But definitely doable, and definitely faster if 10hz update rate is not fast enough.

Title: Re: Peerlink VS Ethernet
Post by: franji1 on October 29, 2019, 07:38:25 AM

If 10 PLCs have to share data with each other, using MRX/MWX or RX/Wx, each PLC must write their data to 9 PLCs.  That is a total of 90 point to point packets at whatever rate.

PEERLINK uses broadcasts.  Each publishing PLC only has to send 1 packet.  10 broadcast packets at a rate of 10 per second.