designbuildguy (Customer) asked a question.
I have a machine where I need 7 stepper motors to be controlled.
My question is this: can I control a stepper motor pulse using the standard speed output on a BRX system?
The HSIO modules gives up to 3 axis controls per unit. One of the 7 stepper motors I do NOT need to be controlled quickly, it’s maximum travel is 3” on a ball screw, most of the action will be less than an inch. If I control with standard speed, I can save the purchase cost of the unit (+/- $220 + ziplinks) and the IO space) just for one more stepper.
Secondly - I can see how I set up the steppers with the axis controls in System Configuration (Do-more Designer 2.8.3 > from the toolbar > PLC > System Configuration). But is there a way to set up standard speed outputs to control the steppers if I’ve already set up my maximum axis in the configuration tool. And if so, what kind of speeds can I expect (how slow will it really be? – remember I’m just moving an inch and it’s not a time sensitive movement).
Any help or info is greatly appreciated.
- Bill
"My question is this: can I control a stepper motor pulse using the standard speed output on a BRX system? "
No, it isn't fast enough to be reliable and also cannot be used in a move instruction as those are tied to axis you set up.
You will want to get another two HSIO modules. Which unfortunately gives you a lot of spare channels since you only need a single one from the second module, but you need it on an axis channel and each module only gives you 3 of those.
Your other option is to control the 7th stepper that is slower with ascii SCL protocol over serial comms instead of high speed pulse. You cannot do as much with it this way, but it may work for you and save the cost and space of an extra module.
edit: but I think only the "advanced microstepping drives" support SCL protocol, which are a lot more expensive than a basic stepper drive so you wouldnt save any money at all if you did that instead of being able to use a cheap drive with an HSIO module.
https://www.automationdirect.com/adc/shopping/catalog/motion_control/stepper_systems/stepper_drives#sort=undefined%20desc&start=0&Port_Protocol_L_s_R__ms=%22SCL%22