These are questions frequently asked by our customers about the Systems Plus controller. If your question is not addressed on this page, contact Envirotronics Customer Support Group.
Question:
RS232C, RS422, RS485, and IEEE488… what are they, how do they differ and why would someone use one over another?
Serial Transmission: involves sending data one bit at a time over a single communications line. Serial transmission is beneficial for long distance communication.
Parallel Transmission: involves sending all data bits simultaneously. Requires as many lines as there are bits in a word being transmitted (an 8-bit word requires a minimum of 8 lines). parallel transmission is designed for short distances, or where very high transmission rates are required.
SERIAL COMMUNICATIONS
The 3 serial standards commonly found in use today are RS-232, RS-422, and RS-485.
RS-232
· oldest and most well known
· supports transmission lengths of up to 50 feet (15.24 m)
· supports connection of only two devices on the bus at one time (normally the computer and instrument)
· 25-pin sub-D is the most common connector (however two different pinouts are used). 9-pin, 9-pin DIN and sometimes even 4-pin connectors are used.
RS-422
· supports transmission lengths of up to 3,600 feet (1, 097 m)
· supports connection of only two devices on the bus at one time (normally the computer and instrument)
RS-485
· supports transmission lengths of up to 3,600 feet (1,097 m)
· supports multi-drop operation (connection of up to 32 devices at one time)
PARALLEL COMMUNICATIONS
The most common parallel data acquisition bus is the IEEE-488 (a.k.a. HPIB and GPIB)
IEEE-488
· consists of 24 lines
- 8 - data transfer
- 5 - control
- 3 - handshaking
- 8 - ground return
· maximum speed of 1 megabyte per second (fast)
· maximum permitted total bus length is 65.6 feet (20 m)
· uses 24-pin connector. Cabling is typically male/male configuration and devices are wired with female receptacles.
· supports multi-drop operation (connection of up to 15 devices at one time)
NOTE: maximum distance between any two devices must not exceed 13 feet (4 m)
This length constraint limits its use in industrial application, however, it is ideally suited for laboratory environments.
›back to top
Question:
What are Lab View Sub VI Drivers? What they will do for the customer, what must the customer do to make them work, and what versions are available?
LAB VIEW SUB VI DRIVERS
Lab View Sub Virtual Instrumentation Drivers enable the Systems Plus to communicate with the user interface package - Lab View. Simplistically explained, it is similar in function to the printer drivers in your PC. Your PC and your printer cannot communicate effectively with one another without the appropriate printer drivers installed. The Lab View Sub VI Drivers enable the communication between the Lab View Program and the Systems Plus. They are intended to be installed on your computer running Lab View.
If your customer has elected to use Lab View, Lab View Sub VI Drivers must be installed (or written by the customer) to enable the program to communicate with the Systems Plus.
The current version of Lab View Sub VI Drivers available is ver. 5.2
›back to top
Question:
What is EMULATION MODE? What will it do for the customer, how does it work, and where is it on a computer?
TWO MODES OF REMOTE COMMUNICATION
EMULATION MODE
EMULATION MODE is one of the two modes of remote communication used by the Systems Plus. In EMULATION MODE, the display of the Systems Plus is echoed to the remote terminal or computer. You will see the Systems Plus display screen on your remote terminal or computer screen.
Emulation mode frees the user from having to constantly return to the chamber’s physical location to monitor its operation. Monitoring can be done from the remote terminal or computer.
Where is it on a computer? Use any communications package that emulates VT100 Mode (Like Hyperterminal that comes with Windows®).
›back to top
Question:
What are COMMAND SETS? How does a customer use them? How do command sets work?
COMMAND MODE
COMMAND MODE is the other mode of remote communication used by the Systems Plus. In COMMAND MODE, a remote source (terminal or computer) may send commands (from the Remote COMMAND SET) to the Systems Plus and it will respond with the requested data, status, or an error (if one has occurred).
The user will enter the desired command (case-INsensitive) from the keyboard of the remote source (terminal or computer) and the Systems Plus will carry out the command as if it was punched directly into its keypad. For example: entering “emergency stop” from the remote terminal will have the same effect as pressing the EMRG STOP or OFF key on the Systems Plus.
Like EMULATION MODE, the benefit of COMMAND MODE is that the user is freed from having to return to the chamber’s physical location to enter commands for operation. Commands can be sent from the remote terminal or computer.
The Systems Plus manual contains a complete list and explanation of the commands available to the user via the remote COMMAND MODE in the Remote Communications section.
Where is it on a computer? Use any communications package that emulates VT100 Mode (Like Hyperterminal that comes with Windows®).
›back to top
Question:
What is the REMOTE EDITOR used for?
REMOTE EDITOR
Envirotronics’ Remote Editor is intended to be installed on your computer. Microsoft Windows version 3.1 or higher must be present to use Remote Editor. This software, with its graphic user interface, allows the user to create , edit, and save programs on your hard drive or diskette for later use in your Systems Plus. Its File Menu Commands (New, Open, Save, Save-As, Close, and Exit) function like most other Windows-based software.
Remote Editor allows the user to copy, cut, paste, delete, clear, and insert steps from within a program, jump back and forth between the steps of a program, jump to the last step of a program, and also allows the user to translate the Systems Plus log files into a comma-delimited text file for use in a commercially available text editor or spread sheet program (like Microsoft Excel).
The benefit of Remote Editor is that the user can create and edit programs from the “comfort” of a PC workstation instead of having to stand at the chamber, punching the program in on the Systems Plus keypad. In addition, the Remote Editor’s copy-cut-paste functions make the addition of repeatable steps, and program looping simple to accomplish and a real time-saver. The saved programs are copied to a diskette for use in the Systems Plus.
›back to top
Question:
How is the DATA TRANSLATOR used for data manipulation and for spread sheet use?
Data Translator
The Systems Plus log files must first be translated before they can be interpreted by text editors or spread sheet programs. The Data Translator option in the Tools Menu allows the user to translate the Systems Plus Log files into a comma-delimited text file for use in a commercially available text editor or spread sheet program for further manipulation, plotting on a graph, etc.
The Systems Plus accepts 3.5” high or double-density floppy diskettes formatted for an IBM or compatible system. The Systems Plus log files are transferred via diskette to your computer (that has Envirotronics’ Remote Editor and Logging Translator already installed, right?). When Translate Log is chosen from Tools in the Remote Editor program file manager, the path and name of the original file and the name and path where you would like the translated file to go may be entered. Which channels you would like to have translated may also be selected. The data will be saved as a comma-delimited text file.
A spread sheet program (like Excel) may be used to open the comma-delimited text file. The information appears in a very clean and orderly fashion in Excel. The data may then be manipulated and graphed.
›back to top
