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How many pulses will your analog proximity receive in relation to the rotation of the shart? Is it 1 pulse per step? You could feed the pulse back in the PLC's high speed counter to monitor the stepper motor actual rotation. So the PLC both generates the stepper pulses and monitor the encoder feedback.

50 steps in 60-100 milliseconds translate to 833 pulses or less per seconds. That is well within the PLC's capability to handle both pulse generation and encoder feedback.

There is no plan to utilize the RTS/CTS control on COMM1.  There is normally no need to utilize flow control because the message exchange with the PLC is usually half-duplex. You send one ASCII string to the PLC and then wait for it to reply. Usually the modem have sufficient buffer capacity to take the message characters without needing the flow control.

The PLC can communicate at 38.400bps, but you can change it down to as low as 300 baud if need be (that will be really really SLOW). Typically 9600bps works great with most modem on the market.

A radio modem supplier who has tested their radio modem with our PLC is key Telemetering (http://www.keytelemetering.com).  They have tested the radio modem to work when the PLC communicate at 38,400bps.

Check the following thread for the contact person:

http://www.tri-plc.com/cgi-local/yabb/YaBB.pl?board=Support;action=display;num=1053447552

If you can find an optical encoder that can output 24V NPN then you can connect directly to the HSC inputs. If your encoder is 5V only then you will need the darlington array to act as the interface between them.

The built-in ADC has a repeatability of about +/- 3 LSB, which for a 10-bit ADC translate to approximately +/-0.3%.

Note that the reading you see on screen is multiplied by 4 because of the normalisation to 12-bit. i.e. for +/- 3 LSB the reading will fluctuate about +/- 4,8 or 12.

If the reading jump more than that, then ripple on the PLC power supply may play a factor if I assume that your 4-20mA simulator has ultra steady power supply.

If you use the PLC's built-in 5V to power a potentiometer and take measurement the reading will be much more stable.

Sorry. Not supported.

The M-series PLC do not support floating point math. But it's 32-bit integer math is good enough for 95% of control system.

There is a FAQ link to this question. Please visit:

http://www.tri-plc.com/cgi-local/yabb/YaBB.pl?board=FAQ

and look for the topics "TLServer Ver 2.0 could not start".

You are right that the current TBASIC compiler doesn't process complexed logical expression the way C language does. Basically a While expression expect a simple comparison expression that could be joined by an "AND" or an "OR" operator.  It doesn't process logical expression within brackets (that may change in future). That's why terse expression like your example will not compile properly.

An equivalent expression is as follow:

I$ = INPUT$(1)

FOR I = 1 TO 20
     X = ASC(strupr$(I$),1)
     IF LEN(i$)=0 RETURN: ENDIF
     IF ASC(strupr$(I$),1)<>65 AND asc(strupr$(I$),1)<>82
         GOTO @5
     ELSE
         I$ = mid$(I$,2,len(I$)-1)
     ENDIF
NEXT

@5  ' Out of loop location

This is really a PLC programming issue and not a technical problem. If you are willing to get paid helps from outside consultant we can ask some of the consultants we know  to help you write the initial part of the program.

Otherwise, we can only offer you a description of how to control your ramp up cycle (ramp up from temperature -45 to temperature B+40 degree C within 1080 minutes). Normally your measured ADC reading is between 0 and 4092. You need to do some scaling to convert them into degree C. Assuming that each digit represent 0.1 degree after scaling, i.e. -45.0 degree means -450, and +40.0 degree is represented as 400:

At the ramp up cycle, the starting temperature is -450.
The end temperature is to be +400
Ramp up time = 1080 minutes

 ==> increment = 400-(-450)/(1080*60) = 0.0131 per second.

You can use a 1 second clock pulse to periodically execute a custom function. Within this custom function, you will increment a variable (say N) to keep track of the elapsed time from the start of the ramp up cycle. You will then compute the desired temperature at this instant and compare it to the measured temperature, then decide if you want to turn ON or OFF the heater:

N = N+1   ' keep track of elapsed seconds from start of cycle.
IF  N > 1080*60    ' times up
    .....            ' do whatever necessary
ENDIF

S = -450 + N*131/10000   ' S is desired set point.

T = ADC(1) * (some scale factor to give readings in 0.1 C)

If T < S       ' Temperature is below set point
     SETIO Heater
ELSE
     CLRIO Heater   ' temperature is above setpoint
ENDIF