[IO-AI4-AO2 reading problem]

Hello all.

I just moved an application from V130-33-TA24 to a V1210 using local I/O and remote via EX-RC1, including IO-AI4-AO2.

V130 used one analog input configured as 4-20 mA coming from a weigh scale indicator which has passive analog transmitter. It uses external 12 VDC power supply (Device requires 8-15 VDC as external power supply) different from the 24 VDC used for OPLC. It worked fine for months.

Now, using IO-AI4-AO2 for same purpose and wired the same way, analog input raw value doesn´t move beyond 10.

Tests already performed:

• Doubled checked wiring and configuration.
  
• Analog input using 4-20 mA simulator (Active): works fine.
  
• Current transmitter signal with digital tester: works fine, reading moves up to 12 mA.
  
• Current transmitter signal with digital tester in series with analog module: reading stands about 1.2 mA.
  
• Using another analog input: Same situation, raw value doesn´t change.
  

The only relevant difference I found between analog module and V130 is impedance for analog inputs.

It seems like this particular transmitter is not compatible with IO-AI4-AO2. I have no information about maximum impedance load from transmitter.

Using a resistor in parallel with analog input would be useful?

Any suggestion would be appreciated.

[New here. Can I use the drum sequencer with inputs or timers only?]

Right, but you also must check current step to make sure you are moving to desired step. It´s also posible to jump to a step other than next one.

[New here. Can I use the drum sequencer with inputs or timers only?]

Then you have to set duration time equal 0 to those steps you want to move by external signal rarther than by time. In ladder, you must use your own conditions and current step index drum sequencer to move next (Or desired) step

[New here. Can I use the drum sequencer with inputs or timers only?]

Drum sequencer is used to set outputs only (Physical or MBs), so I don´t understand why you want to use inputs. Or do you mean using inputs to move between steps?

[Vision 570 PWM Output not working]

Have you checked operand values for frequency, duty cycle and MB that turns PWM on?

If those operands are all set to 0, PWM will not work at all. It can be the cause your second unit doesn´t work either.

[U91 Keypad entry question]

Perhaps a number greater than 327.67 ??

Also check entry limits.

[Pseudo-Parameterized Subroutine w/ Data Tables]

Take a look to:

C:\Program Files\Unitronics\Unitronics VisiLogic_C\Examples\Version 900\Project examples\Data Table\V280_Function_Block_Multi_Process_via_Data_Tables.vlp

[Timer Preset Behavior]

Thanks for info, it´s ver useful.

I´ve always expected to be able to set default (My default) timer preset values such as any other operands, using power-up initialize option.

Those timers which user must not modify, I preset using ML and store timer preset function in ladder.

Clone should be complete.

[Count Data Table Rows]

Lukas, number of rows are fixed when you create/edit data table. There´s no way to modify it by ladder.

Usually I use a pointer to know which row I must write data from. In that way you know how many rows are available.

[Logic analogous to "timer timing"]

I´ve done same application but for security reasons using pneumatic switches and AND gate to close clamp and opening it with electrical signal. This way clamp only closes if operator pushes both switches at the same time (With slight time delay).

[Modbus TCP/IP - V130 as a Master With two V130 as a Slave]

Only 4 active connections socket connections. That is correct.

But doesn´t mean only 4 slaves can communicate with a master, does it ?

Is it possible using a single socket communicate with multiple slaves ?

[IO-LC1 zero drift despite auto-zero]

I suggest you to use a loadcell simulator to narrow the problem. Perhaps a loadcell drifted with a no-steady behaviour

[Create a bit toggle field with V130?]

Maybe using list of texts variable with keypad entry enabled, pointing to an MI, but you have to press up/down keys to change value

[PCOM Writes to plc not happening]

I´ve used this procedure to write a single MI register:

Public Function SetMIValue() As Integer

Dim MI() As Integer

Const Address As Integer = 12

ReDim MI(0)

MI(0) = 433

SetMIValue = mComDriver.Write_MemIntegers(Address, 1, MI)

End Function

[frequency measurment]

You can also use Hardware Configuration, setting high speed input as HSC and frequency measurement linked to an MI or ML. It will give you Hz directly, however its resolution is just 1 Hz.

You must check your wiring as well.

[Timers]

You can use "load timer/counter preset" and "Store timer/counter preset" functions to do that.

[Vision 1040 and EX-RC1 ..2 MODULES]

In ID=4, why do you use #4 as destination in UniCAN Send, Arrived and check alive FB´s? As I understand, it should be #1 to proper communicate with master PLC

[Error Message]

I had same issue a few months ago, using USB-serial converter I was using for years with no problem. And yes, problem was with converter. Just replaced and everything works fine to me since then.

[USB device to serial port]

Anyone knows a way to connect USB bar code scanner to RS232 serial port of V130 ?

I already tried using regular USB-Serial converter, but didn´t work

[Hardware Configuration]

Only analog inputs #2 and #3 are current/voltage configurable, by jumpers and software.

#0 and #1 are for TC, RTD

[reading from Data table in Visilogic]

Just open datatable and place mouse pointer over cell you want to get memory allocation. It shows type of register, length and allocation (FLASH: ## or RAM:##).

[Data Table Write Speed]

I haven´t noticeddifference between writing to registers or database.

Based on frequency you have to record data, I would use database also to getdata from PLC to PC.

[EX-RC1 and Loadcell module]

Thanks Simon, I just wanted to be sure

[EX-RC1 and Loadcell module]

Can EX-RC1 have IO-LC1 or IO-LC3 attached and to be programmed to act as a single and stand-alone bulk-weighing scale controller?

I have 8 scales site-distributed along factory which do not need local display, just local control; but to be monitored from control room. My idea is to have one main OPLC to monitor and distribuited control.

[Interposing Timers]

You may consider using drum sequencer for such application, even you have fixed times between states (Which makes it easier) or programmable times