Sergei Troizky
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Posts posted by Sergei Troizky
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Is this just a general CJ-series rule, or it is mentioned anywhere in CP1 manuals? The reason I'm asking is that I currently have CJ1W-NC213 and CJ1W-EIP21 both being #0 and still fully functional. -
I've used CP1H expanded with one CJ1 unit many times, and the unit# was always 0. Now, for the first time, I have to use two CJ1 units. The question is: should the 2nd unit have a different Unit# only if both units are of the same type, or anyways (have not found an answer in manuals). -
This sounds primitive, as typically there is a Reception_Completed bit triggering the RXD execution. Still, your method may work for simple data exchange. Be aware, that the reception buffer is not being cleared by RXD execution prior to writing newly received data. The buffer is being overwritten by bytes (not by words); non-overwritten rest of the buffer (if the buffer is defined larger than the amount of data received) remains unchanged. Be sure to clear the buffer after processing the received data. -
There is no contradiction. CP1H-CIF01 and CJ1W-SCUxx are absolutely different units. CP1H can accept 2 special units of CJ1 family via special bus adapter. CJ1 modules are costly, but may feature more than one port per unit and support protocol macros. CP1H optional communication boards are very inexpensive. I've never seen the version limitation you refer to, but after all it's under $100- get a proper one. -
There is also 9324-RLD200ENE Mini version, supporting ladder only, ~$850. -
The very first sentence of W451 3-23-2 states: "PROTOCOL MACRO: PMCR(260) Calls and executes a communications sequence registered in a CJ-series Serial Communications Unit." CP1W-CIF01 supports only TXD and RXD. -
Disable BOOTP and DHCP. -
I've used once CX-Drive 1.70.4.21 and had problems with reading parameters from drive. At some point the transfer stalls and then times out. Actually, I never succeeded to upload entire list of parameters by Transfer from Drive button from R88D-GT04H (not tested with other drives). However, the "Transfer Selection from Drive" button works and allows partial upload. Had no problems with download. -
I did not mean you having problems with timer. I mean that your problem is of the same nature.When all the pulses are done, you must execute the instruction as false in the main program, otherwise it remains active forever. -
What do you call "instruction activation flag"? See 8.2.1 Cautions on subroutines and interrupt routine- Countermeasures against latches of devices used in subroutines (or interrupt routines) in the Programming Manual. It does not mention your instructions directly, but I am almost sure this is your problem. -
There is another choice. Why don't you google "Mitsubishi Keyword" instead of asking questions nobody will answer here? -
Some clarifications and tips, in addition to Michael's post. There is no minimum frequency limit for steppers. The reason is to avoid mechanical resonances in the equipment at stepper low frequencies. Also, using minimum frequency reduces positioning time. Blending moves together is not a reason, because new positioning instruction execution always starts from the actual frequency of the port. And by the way, there is no way to retrieve the momentary actual frequency from the port. Here are some observations from my personal experience with CP1H. Until port origin is set, its PV reading will reset after every move stop. Such reset does not indicate being in origin. Writing any value to port PV defines its origin. Whatever value was written, the origin is in PV=0. Port PV cannot be written by INI #2 during output pulses being generated. With the origin set, relative positioning will not start, if the resulting absolute destination is out of over/underflow limits (-2147483648 to 2147483647, 8000000 to7FFFFFFF hex). Absolute motion target is limited to these limits by definition. On position over/underflow by continuous mode pulse train: - Pulse train continues. - PV is frozen on limit value. - Origin is canceled and No_Origin bit is set. "Clear PV" control bit cancels the port origin setting. PV becomes zero and "No Origin" bit activates. If a PLC output is subject to both high-speed and regular ladder instructions: - During active pulse train, an output control by PTO instructions has priority over control by regular ladder instructions, regardless of the instructions order in the program (not tested for interrupts). - The regular ladder logics is being performed continuously,the output state is being monitored and can be used as a contact in ladder, regardless of high-speed pulse train on this output. The result of regular ladder logics processing will apply to physical output after pulse train stop. Set PV INI #2 instruction will generate error if activated during pulse train and will be performed only after pulse train stop, if still active. This does not depend on the instructions order in the program. It is impossible to switch from independent to continuous mode during pulses being generated. Active continuous motion instruction has priority over simultaneous Immediate Stop INI#3 instruction, regardless of their order in program. Neither will set error flag because of the simultaneous execution. Immediate stop will be performed when the continuous motion instruction becomes inactive. If positioning target is redefined during active pulsetrain, the deceleration rate has priority. That is, if actual deceleration rate is not enough to stop in new closer target, it will be overrun with following return. -
Do not rely on intuitiveness and write comments. -
Compared to what? -
Even if FX3G is not more expensive, it may be a matter of programming software. FX1S/N may be programmed in Medoc, and the original FX0N project files, if any, are most probably in Medoc as well. Medoc is available for free now. No need in program conversion from FX0N to FX1S/N. -
FX0S/FX0N are discontinued long time ago and replaced with FX1S/FX1N. Program from FX0N should be fully compatible with FX1S/FX1N. -
Well, here is an example. However, your code, even expanded for all 16 bits will be comparable by size, but still more obvious for understanding. I do not see any advantage in using loop here. -
Well, first of all, forget independent mode for positioning. Use @PLS2 for positioning, it supports both absolute and relative moves. Start with low acceleration/deceleration and increase them only when you see the positioning is correct. Remember, steppers cannot start/stop immediately over certain frequency (so called self-starting frequency). For 200steps/revolution motor, 100-200Hz should work for self-starting. -
I still cannot understand, is your problem the stepper motor behavior understanding or the PLC PTO control. A stepper motor stops immediately itself, as soon as the pulsetrain stops (assuming the drive has no intelligence and is an amplifier only). If, on immediate stop, the motor and load consolidated inertial torque exceeds the motor holding torque, the motor will slip forward and loose expected position. -
Yes, this is what I meant by additional positioning for correction. However, this would be fighting consequence. Better find and eliminate the reason. -
No, it is impossible to increase stepper accuracy, as it is always within one step of the drive (which may be full, half or micro step). Encoder may be used for positioning confirmation, and you will have to perform additional positioning should correction be necessary. -
Not that obvious. Stepper positioning is more repeatable than servo, because the latter has certain positioning done tolerance. -
I have to use Ultra 3000 on my next project; never used it before. It will work in the follower mode. Could not find answers in the manuals, for: - May the gear ratio be set with both Master and Follower values other than 1, or only as 1:n or n:1? - What is the meaning of possible negative value on the follower side of the setting (the manual mentions ±32767 range)? -
PLC operates AC Inverter (a.k.a. VFD- Variable Frequency Drive) by logic level control signals, typically 24VDC, not by controlling the inverter input power. Status feedback signals from inverter to PLC are also of the logic voltage. Relay PLC outputs can produce control signals for inverter, as well as transistor ones of proper polarity. However, a relay unit has no high-speed outputs, and will not allow to use PWM signal from PLC for inverter speed control. A contactor on the drive power input is a safety disconnect, and as such should be controlled by hardware circuits, not by PLC.
CJ1 Unit numbers on CP1
in Omron
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