Internet PLC Forum

The LCD does not handle scrolling automatically. You will need to control it fromwithin your program. Basically you use a variable as an index (e.g. N), and when you press the scroll up/ scroll down button you will increase or decrease the value of N by 1 until the limit is reached. Then your custom function that display the tool list will have to use the value of N as the beginning tool number and display the list up to the maximum number that can be displayed on a single 4 x 20 screen. This should be quite easy to achieve.

The TBASIC language supports IF THEN ELSE statements so it is really easy to achieve. E.g.

IF ADC(1) > 2000
   CLRIO  HEAT1      ' HEAT1 is the label name of heat output.
ELSE
   SETIO  HEAT1
ENDIF
  
For more example programs, please visit:

http://www.tri-plc.com/examples.htm

Windows XP does not allow a DOS program to take control of the hardware (including the com port) so the DOS TRiLOGI program that is used for programming the E10 PLC, when runs under Windows XP, NT or 2000 will have trouble communicating with the PLC.

Your best solution is to use a DOS diskette or Win95/98/ME startup disk to boot your PC into pure DOS mode and then run the DOS version of TRiLOGI software in pure DOS mode.

How is the PLC's output interface to your stepper driver? Is it a direct connection or going through some interface circuitry. The interface circuitry may introduce some distortion on the stepper signal if it is not properly design.  Use an oscilloscope to examine the signal integrity when it arrives at the driver if you involve external interface circuitry.

The PLC normally should be able to output good square wave up to 10KHz. Beyond 10KHz the time spent in servicing system interrupts may become significant and that can have effect on the motor. Are you using interrupt intensive operation such as pulse measurement or high speed counter simultaneously? Are you using any READ_EEP or WRITE_EEP command?

Note that the CPU disables interrupt temporarily during EEPROM write in order to protect integrity of the data. Thus if you write to EEPROM a lot during the stepper output phases then the stepper pulse generated may not be squarish because the stepper output also depend on interrupt to handle the step counting and acceleration/deceleration.

You mentioned "temperature" and "humidity" sensors. Wouldn't these be analog type of output? "TTL" refers to 5V digital logic voltage where > 2.0V represent logic 1 and < 0.8V represent logic 0.

If you can confirm that your sensors is analog voltage of 0-5V you can connect them to the PLC's analog input. But if these are really TTL level (maybe a pulse trains whose frequency represents the magnitude of the measurand) then you can convert the TTL voltage level to the PLC's NPN input level using a low cost ULN2003A or ULN2803A IC. The circuit can be download from the following link:

http://www.tri-plc.com/appnotes/TTLtoNPN.PDF

Your are controlling AC load using your SSR? Then PWM may not be the suitable choice since PWM is used to chop up DC voltage into deterministic duty cycle and typically operates at several thousand Hz. In your case you probably have to turn ON and OFF at much slower speed. It may be still possible if you use the lowest frequency (16Hz) PWM but do check with your SSR supplier to find out if a zero crossing or instant on type is more suitable to be driven by the PWM.

We don't have our own OPC server for our hardware. But there are generic OPC server on the market that have been used successfully with our PLC. If you like more info, you can contact our Canadian distriutor DCI Technologies who is selling an OPC server that works with our PLC.

Contact:

DCI Technologies Inc:   Tel: 1-403-720-4885
Contact: Ted Skinner
URL: http://www.dcitech.com

For long distance communication, we recommend using the RS485 for your programming. You'll need to purchase an Auto485 converter ($49) to convert your PC's RS232 port into RS485 signal and then connect twisted pair cable from the Auto485 output to the PLC's RS485 port.