Internet PLC Forum

I have a mature program. No more changes to be made.

Is it possible to have a One Time Programmable PROM created to replace the M2017P?

The program does not use the M2017P other than for the original program storage.

Thanks
Ben

Has anyone attemted to use/run Trilogi3.52 under Microsoft Pocket PC v2003, or Windows CE operating system Pocket PC edition, Microsoft Windows Mobile 5.0?

The photo of the EXP4040 shows the ability to handle Encoders and Interrupt signals, is this additive to the 2 channels already on the T100MD-888+? Meaning can you have more than 2 encoders on one MD100-888+ PLC? Nothing is mentioned in any manuals about the EXP4040 and HSC Inputs.

Your assistance is appreciated

I would like to connect a Quadrature encoder to a T100MD-888+,  say 128 PPR,  to HSC[1] and also feed one of the A or B signals into pin #5 as Interrupt Channel #3. This would allow me to synchronize reading A/D signals to every ( maybe ) rising pulse of the encoder.

The ISR ( Interrupt service routine ) would read 4 analog channels, and the value of HSC[1], do some processing, and then display the results on an LCD.

From an earlier discussion on timing, the moderator said

"The minimum scan time of the PLC is therefore = logic scan time (approx. 10us per word) plus I/o scan time (minimum 2ms)."

So if a program was say 1600 words long, I would expect a total period for one interrupt at 1600 x 10 us + 2 ms = to about 18 ms.

This would give me a maximum of say 50 interrupts per second.

What happens when the PLC see's incoming Interrupt pulses at a rate greater than 50 hz?

Is the interrupt input disabled when the ISR is processing, ( non retrigerable one shot equivalent ) and then re enabled when the routine is complete?

In other words, if the Interrupt is coming in at 150 Hz, will we still see a 50 hz. throughput, or will some error occur, and halt the PLC?

Your assistance is appreciated

In a previous query, I asked what the effective input impedance was for the T100-MD-888+, and was told ( May 6 and 7, 2004 )

"there are already 2.2K resistor in series with all the AD1 to AD8 and AD1 to AD6 has 0.1uF capacitor in parallel to filter out high frequency noise on the analog inputs. AD7 (DA1) and AD8(DA2) do not have the 0.1uF capacitor."

As it turns out, the 0.1uf capacitance is presented directly to the DB15 pin, then the resistor is in series to the input to the CPU.

This effectively presents a capacitave loading to any source feeding it.

I have just run into this problem, with an op amp feeding the A/D inputs, and when connected to the T100MD-888+, the opamp( LTC1637) output showed an oscillation riding on a dc level.

I proceded to remove the CPU, and the problem persisted. Examining the T100MD-888+, and following traces, showed me that the 0.1uf caps were connected directly to the DB15S connector, then connected trough the 2.2 k resistor to the CPU. Shouldn't the resistor be presented first, then the cap for a RC filter?

The solution in my case was to install a 348 ohm resistor in series with the Op amp output.

So choose your op amps carefully, for use with the A/D inputs of the T100MD-888+. They require the ability to drive 0.1 uf capacitive load.

All comments are appreciated

What is the effective DC input impedance of the Analog Inputs on the T100MD-888+?.

Some of the literature indicates a 2k resistor in series with the inputs, and the forum has indicated a 0.1uf cap across the input to ground on channels 1 to 6; channels 7 and 8 donot have the cap.

What would be the effective output impedance of Channels 7 and 8 if used as Analog outputs? Do these channels have the 2k resistor in series as well?

Your assistance is appreciated

I have a requirement to count the total number of pulses produced by an optical encoder connected to the T100MD-888+.

I have the A and B signals on Inputs 5 and 6 with HSC[2] and are using PMON 1 Input 3 to measure the frequency.

I have connected the A phase to both Input 3 and Input 4 thinking that I may be able to count the pulses through Input 4, measure the frequency through Input 3 ( PMON 1 ), but It does not work.

Is there a way of being able to count the total number of pulses created by the encoder? As it is now the variable will come back to zero when the encoder rotates in the reverse direct back to home base.

What I want to measure is the total round trip, i.e total pulses, both forward and reverse.

Any suggestions without having to disable the frequency measurement?

Your assistance is appreciated.