Host Engineering Forum

General Category => Do-more CPUs and Do-more Designer Software => Topic started by: RBPLC on August 13, 2020, 07:14:08 PM

Title: Greater Number of Local Add on Modules
Post by: RBPLC on August 13, 2020, 07:14:08 PM
Are there plans/possibilities of expanding the local card expansion on BRX to more than 8? Are there any plans for any "local" expansion as opposed to "remote Ethernet" expansion? 
Title: Re: Greater Number of Local Add on Modules
Post by: BobO on August 13, 2020, 11:28:12 PM
Are there plans/possibilities of expanding the local card expansion on BRX to more than 8? Are there any plans for any "local" expansion as opposed to "remote Ethernet" expansion?

It is logically possible, but technically unlikely. The ad hoc backplane has presented a number of timing and noise challenges that become more troublesome the longer the run.

We will eventually get around to a rack-based cousin of BRX, and it will definitely support more slots.
Title: Re: Greater Number of Local Add on Modules
Post by: RBPLC on August 14, 2020, 05:35:13 AM
It's good hear the plans for the rack based system.
Title: Re: Greater Number of Local Add on Modules
Post by: Garyhlucas on August 14, 2020, 07:38:28 PM
On the Chinese CNC drilling machine that I am controlling with a BRX instead of a CNC controller I suddenly realized I could save a lot of cabling by using 3 BRX PLCs instead of one with expansion modules.  So I am going to have one BRX in the motor controller cabinet controlling the 3 servo drives and 8 VFDs.  Then an ethernet cable through the energy chain to the X axis with a BRX controlling 12 solenoid valves and about 12 proximity sensors. Finally a BRX in the base to control another 12 solenoid valves, door interlocks, product detection proximity and photoeyes.

The cost per I/O point is low and having all the same PLCs reduces spares inventory.  If my scheme for automating this machine works the labor savings and reduction in mistakes will be truly huge for this company that has been doing it the same way for 40 years.
Title: Re: Greater Number of Local Add on Modules
Post by: franji1 on August 15, 2020, 02:32:59 PM
On the Chinese CNC drilling machine that I am controlling with a BRX instead of a CNC controller I suddenly realized I could save a lot of cabling by using 3 BRX PLCs instead of one with expansion modules.  So I am going to have one BRX in the motor controller cabinet controlling the 3 servo drives and 8 VFDs.  Then an ethernet cable through the energy chain to the X axis with a BRX controlling 12 solenoid valves and about 12 proximity sensors. Finally a BRX in the base to control another 12 solenoid valves, door interlocks, product detection proximity and photoeyes.

The cost per I/O point is low and having all the same PLCs reduces spares inventory.  If my scheme for automating this machine works the labor savings and reduction in mistakes will be truly huge for this company that has been doing it the same way for 40 years.

Fantastic!  Distributed High Speed local control, with a "main" PLC talking with the other 2 (or every PLC sharing data with each other) is a great solution.  If Ethernet I/O is not fast enough (it's pretty fast BTW), then utilizing multiple "local" controllers near the High Speed I/O devices is a good design.
Title: Re: Greater Number of Local Add on Modules
Post by: Controls Guy on August 15, 2020, 06:47:36 PM
What's the advantage to BRXii vs EBCs?   You have stuff that has to go in the local base, or using high speed i/o on non-M BRX?