What software do you use for cyclograms?

[Penko Mitev]

Guys, I wonder something. Is there any suitable software for cyclograms? I mean, I want to add all durations in a machine and to see what is the machine cycle time. Of course, it must has to ability to support overlapping times. What is also should report is "dead times". I am calling "dead" the times where the machines makes nothing else than a certain action while time machine is waiting. I hope you got the main idea. By the way, what is there any other word for "cyclogram" in English? Penko Edited January 31, 2010 by Penko Mitev

[jstolaruk]

I haven't see the use of cyclograms in machine time study analysis yet. Generally, when a machine is first designed, we come up with what would be considered normal cycle times for each movement in the machine & a timer is used to measure that time while the machine is running. A specific HMI screen will display each machine movement with its design cycle time and its actual cycle time and highlight if the movement is "overcycle". That and along with a part-to-part timer for the overall cycle time. If the machine is waiting for parts, "starved", or unable to pass parts on to the next process, "blocked", these times are also displayed for each cycle and the accumulated "starved" & "blocked" times for a set period. Sometime we'll provide a pareto chart of the "overcycle" times so that a maintenance person can focus in on the worst offenders.

[Penko Mitev]

jstolaruk, I catch the main idea of your post. You solve the problem with programming. I was talking about, let's say you have a machine assembling some parts. There are certain movements(for example only discrete ones, pneumatic cylinders) and each of them takes some time. You additionally have timers where necessary or where the cylinder works without a sensor. Therefore, in order to create a cyclogram, what we do is to measure all times and try to put them in an excel spreadsheet so we can consider what can be improved(in most cases "timers" are the ones which can be lowered). Your suggestion is applicable when a HMI is available. In most of our assembly machines, where there is no need of HMI, we don't put one, therefore having such screens is not possible. Anyway, thank you for the suggestion and sure I will try it when having a machine requiring HMI. Penko

[ssommers]

Cyclogram is a pretty good term for the machine cycle charts I've made in the past. I also use an Excel spreadsheet to create simple ones using XY Scatter chart type. My basic timer measurements are made off of Start movement & Movement finished bits in the PLC logic. (No HMI needed but I have to have my PLC programming software active to see the timers.) Once those are items defined, I can make timers to go from Start movement #1 to Start Movement #2 if I know that Movement #1 won't be finished. The only thing I don't measure per cycle is Idle time between parts. Idle time goes into a cumulative timer and gets divided by the number of parts made per run (Machine Start to Machine Stop). Once I have all the start times & durations, I can put it into Excel and determine if timers can be reduced or if I need to speed up a cylinder motion. Remember, just because a particular motion takes longer than any other one doesn't mean that you can always make it shorter. Sometimes trying to make things run too much faster makes the machine fall apart. The key is to balance speed with efficiency. A slower machine may reliably make more parts than a faster one that breaks down every half hour. I've been there & done that! Once you get some of the cycle times identified (including normal idle times), you could implement the starved indicator using a flashing stack light. Over cycle time can be done the same way if there's a problem that stalls the cycle.

[Peter Nachtwey]

This is what I use. The data acquisition for the cyclogram is built into the motion controller. There is also a log the logs events down to the millisecond. All of this is accessible over Ethernet. http://www.deltamotion.com/peter/Videos/Fl...FlyingShear.mp4

[Penko Mitev]

Thank you guys both about the comments! Peter, it's not a question only of motor-controlled devices(VFD, Servo, Step motors...). It's also a question of pneumatic-actuated devices and their action durations. @ssommers, what you have written generally resemblances our problems. Most devices in our machines are cylinder-driven and in most cases just a few are motor-controlled, so our case seems identical. Excel is what my father does, but there must be an easier way. Thanks once more! Penko

[panic mode]

i just use PLC. simply each and every of my projects have cycle time monitoring (overall and per sequence step) which is more than good enough and makes optimizing easy.