panic mode

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About panic mode

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  • Birthday 12/15/69

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  1. Replacing thumb wheel

    i think last time those were made was in the 70s. they may be falling apart on their own, without user touching them. why not use something more recent like HMI? you get way more bang for the buck... or use panel mount LED/LCD counter module as a display, together with encoder or pair of buttons (increment/decrement) as input.
  2. Set Carry e Clear Carry.

    it is the same thing you do when adding numbers by hand using nothing but a pen and paper.   for example adding  597 and 895 597 895 (+) ------ ????   so you start from the right side (least significant digit) and add those values 7+5 = 12. so you write down 2 (result is ___2)and remember to carry 1 (representing 10 actually) to the next position. then you are adding 9+9 but also must include value that was carried over (1) so sum here is really 9+9+1 = 19, and you write down 9 (result is __92), and carry 1 again. then you have 8+5 and since we still carry value from previous digit addition, it becomes 8+5+1=14. so you write down 4 (result now is _492) and you continue to to next position. since there is no more digits in the operands, we just have the carry (1). we write this down and result is 1492. if this was clear, you should have no problem adding numbers that have many more digits.  same is with the computers - they can only handle limited chunks of data (based on instruction type and size of registers). so to break free from this limitation and be able to handle even very large values, carry value need to be considered. and programming manual has the nice example as well. before calculation one would reset the carry flag. setting flag is possible too but this is used less frequently    
  3. Need a simple 1 second pulsed output with button push

    can you please just get to the point and tell us something about function you need: 1. what is the exact PLC model  2. what is the PLC software type and version 3. what is output really supposed to do if you want to make single 1sec pulse when button is pressed, and really make it 1sec pulse regardless how long the button was held  down, something like this  should do explanation X5 is input for push button (trigger). instruction is not a standard NO contact but senses rising edge (hence the arrow up). this ensures that regardless how long button is press down, only single pulse will be generated.   rest is a simple seal-in logic: output Y4 is held on until timer T4 times out. K10 is duration  (10x base time). on most timer base is usually 0.1 seconds. so 10x 0.1sec = 1 sec.
  4. Hello 

    I am captain of a sailing vessel that is equipped with a Mitsubishi PLC System that control Wago fieldcoupler on a profibus network. My knowledge in PLC world is extremely limited and I am looking for help.  The company that originally did this installation does not exist anymore. So I wanted to know if you could direct me in my research of a company that could help troubleshooting and resolving my problems. At this stage of problem understanding  the Mitsubishi module QJ71PB92D indicate RSP ERR. which in my research interpret as a communication trouble. If I follow this logic I would need someone that can test the network but this might not be the only issue.

    This system was put in service in 2005, has been working correctly since I joined the vessel, and recently started to act on me.

  5. Shifting data by bytes

    What is the CPU type? That will determine instruction set. Then you can check what options are available - there could be suitable instructions for this... But you can always manipulate data yourself. For example to extract lower byte, just AND the value with 255. To get the upper byte use swap instruction then again and the value with 255.    
  6. AB Networking suggestions

    when it comes to Ethernet/IP, AOP is used to allow single network interface to be used both for standard and CipSafety data. one can of course choose to not use AOP for this then one needs additional network card. it is same as working on PLCs with older firmware.
  7. problems with CP1H analog input

    post your code. are you checking error flags (A434.xx)? are you measuring current with a multimeter to confirm it is really in that range?
  8. Mitsubishi Q and SMC JXCD1 Devicenet module

    add card into PLC rack and note the head address. perform correct DNET wiring and termination.   just like other fieldbus types: a) all nodes are wired "in parallel" (hence the bus). b) on the two extreme ends of the bus need suitable terminations (121 Ohm 1% resistors). c) while it is possible to use trunk/drop style wiring, there are limitations, particularly on length of the drop. Preferred way is to have no drops. d) all nodes need unique address or MacID e) data exchange for the most part is cyclical (master is polling slaves). in rare instances there may be need for explicit message. normally this is used to configure slave or transfer large block of data that exceeds size of mapped IO blocks.   note unlike other bus types (ProfiBus etc.): a) DeviceNet bus also has conductors for power and you need to provide that 24VDC (it is not something that is obtained internally). b) terminating resistors are normally discrete components and resistor leads tend to be exposed - it is a good idea to add protection (i prefer clear heatshrink). On other busses they tend to be integrated into connectors or molded into suitable shape. c) Unlike Profibus for example, bus speed settings is usually done at each and every node, although there are some products that can autodetect baud rate.   next part is software configuration. this means obtaining EDS for each slave. contact slave manufacturer to get them. according to JXCD1 manual, EDS can be downloaded from the SMC website: i just glanced it and see IODD file for IO-Link but not EDS so perhaps specify exact product name (JXCD1S or whatever) or call tech support. on second look, one just needed a minute or so do deeper search specifically for DeviceNet version and EDS file is found at: or direct link then the master need to be configured by building scan list. have not done this on Mitsubishi so cannot help much there. the idea is to add matching EDS for each slave to master configuration and parametrize it. in simplest case that means stating the node address but you may also need to specify size of IO blocks that node will send or receive. Finally there will be some code. Normally this is just few lines to initiate data exchange and handle diagnostics (missing slave etc.) and of course do the data exchange between master and controller. Normally all of this (including code examples) is in the product manual. In Mitsubishi tradition, programming documentation tends to show examples for intelligent modules using head address zero and you would of course need to change it to match your PLC configuration. if you are new and confused by this, perhaps consider placing this module next to CPU. for more help or interpreting data in the documentation, post the links to actual manual(s) so we don't need to look them up. example  ps:// <EDIT> and AndreasW already posted link to Mitsi manual.       
  9. DeviceNet powerflex 40 faults

    lowering baud rate does improve signal integrity. this is obvious even from reading installation guide, since it is possible to have longer bus network if the baud rate is lowered. this is not disputed. cables have capacitance and inductance so they can distort the signal. this is why bus is to be treated as a transmission line which is the reason for correct termination. and it looks like you did receive product that is forcing you to use different settings. sometimes that is all one can do. fortunately this is pretty rare.
  10. DeviceNet powerflex 40 faults

    just about all problems with DeviceNet that i have seen were due to wiring. even people that do not understand networking manage to find configuration that works, even if takes bunch of attempts. but when something is wrong with the hardware (wiring, termination ,shielding) no amount of poking at settings will get you though.  since the line was working before, and you are backing up and restoring settings, there is no reason to doubt parameter settings. lowering baud rate is usually last ditch effort. Sometimes it may help but there are no guaranties. one example where that does work is if one or more of devices use autodetection of baud rate. on a noisy network they may have better chance when baud rate is reduced.  as for troubleshooting tips, i would say if not already done so try following: measure resistance across data lines to confirm it is 60 Ohm (pair of 120 Ohm resistors in parallel). if not correct, one of the terminators is not connected or there is a lose connection on one of the bus lines. it could also be that the bus is over-terminated (more than two terminators present).  check voltages at each node on every terminal with respect to black wire. should be about 2.4V on blue wire, about 2.5V on white, 0V on shield and 24V on red. check if the bus is really a bus topology. if there are dropped nodes, check the cable length of the drops. drops need to be short, do not remember the specs but if i recall they should not be more than 3m or so. check if the bus shield is grounded at ONE place only. if the cable was damaged (jacket has abrasions, punctures by metal chips etc) because it may be acting as a second grounding point and ground loops will have terrible effect on signal integrity. also check cable routing. communication cables should be always routed away from sources of noise. if possible try to shorten bus (just for testing) to see of the problem persists. this is one thing that is done nicely on ProfiBus - just move terminator switch on any node in the middle of the bus and (if the bus is wired correctly) that is the only hardware change. doing so on DeviceNet is a bit more effort.
  11. How to make a recipe Delta PLC?

    yes, rolling own code is not hard but there are limitations. which is why recipes are normally HMI functionality as they tend to have more memory and response time is less critical.  
  12. How to make a recipe Delta PLC?

    don't know those platforms but some may have the function for that and if not the idea is to make an array of records - if the controller supports user defined structures. if that is also not available, just use parallel arrays of suitable type and size.
  13. Reading an integer from a table.

    whatever platform you are working with, you need to have your reference documents for that platform at your fingertips. and SLC500 is no different.   SLC supports indirect addressing so it is not a problem to access register using an index. it is same as using an array. suppose you values are in table N27 and index value is in N7:34 and the result is in N7:35, you can use something like SCP I4:0 3277 32767 0 250 N7:34; scale analog input with raw values range 3277-32767 to an engineering units 0-250 ton and place result into N7:34 MOV N27:[N7:34] N7:35; get value from lookup table N27 and put result into N7:35 based on scaled analog input value but... using the integer data table as a lookup table to get result means you only have 250 values that can be displayed (no decimals). and while that may be sufficient and meet your application requirements, it does sounds pretty low resolution compared to what one normally gets from the sensor.
  14. did not use Fanuc in ages but there can be some differences: as i recall Fanuc robots only use two stop types (0 and 2).  stop 2 is a programmed (controlled) stop which is when robot reaches target point while controlled by program. stop 0 is used in case of an error or fault or safety stop (estop, fence etc).   in case of stop 2, robot should always be on path - regardless if stopped or not. in case of stop 0, brakes are applied and motors are deadlocked (short circuit breaking). so from this moment on and until robot comes to a rest, robot is actually out of control and possibly no longer on path. think of one axis as a car without ABS that was moving fast and then wheels are locked... as expected, car will slide in the general direction in which it was traveling. some cars may remain on the road, some may end up in the ditch, its hard to give precise prediction... now back to the robot. each axis is another car. and each is different. so each will decelerate on its own depending on torques acting on it and obviously this depends on many factors: robot type, assigned payload, actual payload, pose, speed and trajectory at the moment of interruption, number of axes in motion, coefficients of friction, state (wear) of the individual brakes, gear ratio at each axis etc. so the place where robot actually ends up will be more complicated because EOAT depends on position of all joints. but it will still be in the general direction in which was moving initially. the question here is how the recovery works and that is something that may be product or brand specific so check the documentation, ask Fanuc or test.   Nowadays I work with KUKA which also supports stop 1, and that means more complex behavior. Naturally there are more possibilities where the robot may end up in the case of stop. One nice feature here is that KUKA will always do a BCO if not on path. This function is moving robot at reduced velocity until on path, then stops and waits for another start. The exception is the EXT mode which does not do a BCO. This is type of auto mode in which robot is controlled by something external (PLC), equivalent to using PNS on Fanuc. So in this mode, blindly clearing faults and issuing start will make robot move like before - without BCO and without speed reduction (even if not on path). Obviously when commissioning/programming is not done correctly this could be a problem. For example PLC does not see if robot is on path or not on its own, so blindly issuing another start in EXT is a great way to create a lot of carnage. Which is why KUKA recommends to stick with manual recovery in T1. This makes sense since auto recovery needs proper solution and here - attention to detail is pretty important.
  15. Emerson (Prophecy) vs. Rockwell (A-B) Lets be real...

    acquiring another skill is always a plus and you never know when it will be handy. more importantly, continuous learning helps one be flexible and open to change. i have worked with many PLC brands (AB, Siemens, Mitsubishi, Omron, Beckhoff, Schneider, etc.). knowing any one of them would be more than enough to keep me busy and employable but that never stopped me from trying to learn more while trying to retain as much as possible. as a result PLCs are important but only a part of what i am good at. i like learning and and would not change a thing. knowing more gives me the edge. also there is a freedom to choose even when things get hard and others may be struggling to just stay afloat. when there is a shakedown, first to go are the temp workers and those with limited skill set. and i have seen many people come and go, while i move when it suits me - salary, benefits, hours, travel, work climate, location, etc. so everyone has unique needs and should decide what works for them. if you think it is the best for you to move on, don't let others stand in your way. change can be good but even if there is a regret, it is better to be because of own choice, than someone else's influence.