EC32 - Driver modules

Driver modules are used to create tasks, which can communicate through one channel with one hosting application module. Drivers are the primary interface to hardware components.

Scanners
Numerous implementations for different scanner models of Sick and Datalogic have taken place as point-to-point and as network connections. Further implementations are possible in a rather short time, if the appropriate specification is available from the supplier.

3964R
The module 3964R provides the functionality for a serial communication using the protocol 3964R. Many applications and devices like scanners and portable data carriers are using this protocol.
The significant parameters for the module are stored in external parameter files which allows a modification, for example of the port number, baudrate, parity or the priority, without touching the software.
The system accepts baudrates from 110 through 115 k Baud, even, odd or none parity, 7 or 8 data-bits, 1 or 2 stop-bits and port assignments from COM1 trough COM8.

RK512
The module RK512 provides the functionality for a serial communication using the protocol RK512. This protocol was specified by Siemens and is mainly used in combination with a Siemens PLC.
The significant parameters for the module are stored in external parameter files which allows a modification, for example of the port number, baudrate, parity or the priority, without touching the software.
The system accepts baudrates from 110 through 115 k Baud, even, odd or none parity, 7 or 8 data-bits, 1 or 2 stop-bits and port assignments from COM1 trough COM8.

External Display Siebert
A special driver has been developed for the connection of SIEBERT large sized alphanumeric character displays.

Digital I/O
This driver allows the control of up to 32 digital inputs and outputs through one or two digital interfaces. In general they are used for the utilization of a signal exchange between process controllers or PLC’s and the DCP application or to set digital signals for alarms or indicators.

INTERBUS-S Master
Instead of using the digital I/O driver with its limits of up to 32 IO points it is possible to use a special interface board (PHOENIX CONTACT), IBS PC ISA SC/I-T. This technique does not require extensive installation measures in the computer cabinet and has a much higher range of modules available than the standard IO driver.

Printer
The available printer driver uses a serial COM port or alternatively the parallel printer port. It was designed for simple text output only due to the fact that there are thousands of different printers on the market, most of them having a specific control language.

NET485
This driver provides the functionality of a simple and cheap RS485 network with a central master station and up to 31 slaves. The technique used follows polling principles.

UDP/IP
The UDP driver was designed in cooperation with the VW department KDO-B in order to connect FIS systems with remote front-end-systems like the applications mentioned in this documentation.
The reason for not using TCP-IP is related to the fact, that TCP is a connection oriented data transmission, which implies, that before data transmission can take place, a connection between two adjacent sockets has to be established. During the software tests it was found, that sockets, which were not correctly terminated or released, did remain in memory consuming dead resources. Since this was not acceptable for a process-control-environment VW decided to use the connectionless UDP protocol.
Unfortunately UDP has some kind of "transmit-and-forget" behavior making data transmission not very reliable. Together with VW it was agreed upon a functionality of a software handshake in the driver layer. Each transmitted message is embedded in a frame, which is checked by the receiving UDP driver and acknowledged upon correct data.
Furthermore, VW required redundant system communication:
The UDP driver in its current implementation is capable of addressing up to 32 different host systems. Additionally it has a list of nodes, where up to four alternative IP addresses may be defined for each host connection. In the case of a broken communication with one host, the driver will cycle through the list of alternative nodes in order to find a redundant host system. If any host was found, the driver will lock on this new node and resume further communication. Also this list is included in an external text file:

TCP/IP client
For the connection of COM-servers from Wiesemann & Theis, Germany, a TCP client has been implemented, which allows a dramatic increase of the number of available COM ports in the system. Remember: COM ports all require an available interrupt, there are only a few available. Shame on Intel!

Profibus FMS
The new implementation of a profibus driver now allows the connection to intelligent profibus compatible components.