Looking for different communication possibilities.
09 Apr 2017 01:30 #91066
by tommylight
Replied by tommylight on topic Looking for different communication possibilities.
Yes, step/dir is a posibility.
Yes you can use modbus to control VFD, i doubt it can do any kins and i read that it is a userspace component, not realtime.
Ethernet can be used with Mesa cards or Beckhoff devices, have a look at ethercat.
Parallel port is an option, realtime, can controll machines easily but limited for IO, 12 outputs and 5 inputs per port, adding add on PCI cards is also possible. It can control step/dir drives, do PWM, used for 5 inputs ( 9 inputs in X mode, limiting ouptuts to 8 ). In most cases can do up to 20.000 pulses per second, some computers will do more ( i have an older xeon workstation that does 50.000 easily ).
Usualy winches are not very diferent from CNC machines as they do forward/backward, left/right and up/down. Using Linuxcnc to controll it, it becomes a huge pick and place machine. Hmmm nice idea.
Yes you can use modbus to control VFD, i doubt it can do any kins and i read that it is a userspace component, not realtime.
Ethernet can be used with Mesa cards or Beckhoff devices, have a look at ethercat.
Parallel port is an option, realtime, can controll machines easily but limited for IO, 12 outputs and 5 inputs per port, adding add on PCI cards is also possible. It can control step/dir drives, do PWM, used for 5 inputs ( 9 inputs in X mode, limiting ouptuts to 8 ). In most cases can do up to 20.000 pulses per second, some computers will do more ( i have an older xeon workstation that does 50.000 easily ).
Usualy winches are not very diferent from CNC machines as they do forward/backward, left/right and up/down. Using Linuxcnc to controll it, it becomes a huge pick and place machine. Hmmm nice idea.
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12 Apr 2017 22:32 - 12 Apr 2017 22:39 #91273
by bkt
Replied by bkt on topic Looking for different communication possibilities.
ok dab77 .... not understand very well your problem about distances .... probabily because I'm not familiar with all winches mechanical design. With 7i77 I make cartesian paletizer with 45mt of cable for "a" axis, 40mt for "y" , 35mt for "z" & 28mt for "x" ..... motor x-z axis of 2.5kw, y 1000w & a 200w. For electrical part I think winches and paletizing robot (cartesian type) is not so different.... x = 5500mm Z = 3400mm Y = 2400 mm all to 60mt/min max vel ....
If you use ethernet/serial mesa cards, you must make an electrical box near every motor ... I understand well your ideas?
In these case consider the difference between cable cost and electrical box ... I think cable is better. If your spidercam is a spider delta robot I think cable is suitable. If your spidercam have usual late/mill velocity (15mt/min max) you can use for shure ethernet cable and mesa ethernet or serial card. I not love the surprise, and in my experience EtherCAT also suffer if you fly too many axes with high dynamics. I talk about close ethercat not open version.
....
Now I work of imagination and imagine that you have many inputs and outputs associated with each axis .... pressure, tension cables, brake winch, temperature control and other ... In these case you have 3 option: 1) your ideas (mesa ethernet: motion control + io near interesting point) ... 2) You can have 3 cables for motion control (motor power, encoder cable cable) + can bus/ethercat for remote plc io (+power cable for remote io) .... 3) as option 2) but with multipolar cable or bus cable for junction box for io (no remote plc module but juntion box). These structure request Lcnc + pc for motion control and HMI & std plc for io control + emergency chain. More respectful of the regulations for industrial environment than use only Lcnc for pilot all. Plc has its certification, and Nobody care who pilot servomotor if the emergency controls and safety are related to the safety plc.
But other can have ideas better than mine.
regards
Giorgio
If you use ethernet/serial mesa cards, you must make an electrical box near every motor ... I understand well your ideas?
In these case consider the difference between cable cost and electrical box ... I think cable is better. If your spidercam is a spider delta robot I think cable is suitable. If your spidercam have usual late/mill velocity (15mt/min max) you can use for shure ethernet cable and mesa ethernet or serial card. I not love the surprise, and in my experience EtherCAT also suffer if you fly too many axes with high dynamics. I talk about close ethercat not open version.
....Now I work of imagination and imagine that you have many inputs and outputs associated with each axis .... pressure, tension cables, brake winch, temperature control and other ... In these case you have 3 option: 1) your ideas (mesa ethernet: motion control + io near interesting point) ... 2) You can have 3 cables for motion control (motor power, encoder cable cable) + can bus/ethercat for remote plc io (+power cable for remote io) .... 3) as option 2) but with multipolar cable or bus cable for junction box for io (no remote plc module but juntion box). These structure request Lcnc + pc for motion control and HMI & std plc for io control + emergency chain. More respectful of the regulations for industrial environment than use only Lcnc for pilot all. Plc has its certification, and Nobody care who pilot servomotor if the emergency controls and safety are related to the safety plc.
But other can have ideas better than mine.
regards
Giorgio
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