DCENET Data Collection Program
Overview
The DCENET program is used to capture factory/shop-floor data over an Ethernet
LAN from network data collection devices. It is specifically designed
to work in conjunction with the
ET210
series of Ethernet data collection products manufactured by Computerwise,
Inc.
The DCENET program establishes a TCP/IP connection with one or
more data collection devices on the network. It presents each
terminal with a logical series of prompts, captures operator responses,
validates them and stores them as records in an ASCII data file.
The captured data records can then be used by another application
for processing. Applications include (but are not limited to):
- Factory floor data collection
- Time & Attendance
- Access control
- Machine Monitoring
- Shop floor data capture and data collection
- Factory floor data capture and floor data collection
- Manufacturing data collection
- Labor data collection or labor tracking
Theory of Operation
The DCENET program will capture real time data from multiple data
collection devices attached to the network. Prompts are presented
to the operator in a user defined sequence and operator responses
are validated and then stored in a data file. The heart of the data
collection functionality is provided by a Configuration File which
is read by the program when it is started. It is used to build the
application tables and control the flow of the data collection process.
A Terminal Table is used to specify the network terminal devices
and their associated IP addresses. The DCENET program can operate
in either a Client or Server mode. In Client mode the program
will attempt to establish a network connection with each terminal
specified in the Terminal Table. In the Server mode the program
will wait for the terminal device to request a connection and
will accept only an IP address included in the Terminal Table.
Once a connection is established the program will send a prompt
to the terminal device and wait for an operator response.
The prompt sequence is defined and controlled by a Prompt Table
which also defines how the operator response should be processed.
Once the terminal operator enters a response it can be validated
in several ways. If the response passes all validation tests the
next logical prompt is presented to the operator. Valid responses
can trigger a special operation such as activation of the bell
or a relay. If the response fails any of the specified validation
test an error prompt can be presented to the operator.
Valid operator responses can be included as a data field in a
captured data record. The response data field associated with
each prompt can trigger the beginning of a new data record and/or
saving of the data record to the data capture file. Each captured
data record can include one or more response data fields and optionally
a time and/or date stamp. Captured data records are stored in
an ASCII delimited data file defined by the associated prompt.
In addition to capturing operator response data the DCENET program
can trigger an alarm event. Each alarm is defined by an entry
in the Alarm Table and is set for a specific time of day. Typically,
alarms are used to activate the terminal bell or a control relay.
Alarms can be used to signal the beginning/ending of a work period
or to start/stop a control process.
Client Mode
The default operating mode for the DCENET program is the Client
mode. In this mode the application program is responsible for
initiating a connection with the data collection terminals. When
the data Capture function is started the program will attempt
to establish a connection with each device specified in the Terminal
Table.
Server Mode
The DCENET program can be configured to operate as a server application.
In this mode the client data collection terminal is responsible
for initiating a connection with the application program. When
data the Capture function is started the program will listen for
a connection request and will accept connections for devices specified
in the Terminal Table. One advantage of this mode over the default
Client mode is the ability to locate the data collection terminals
behind a firewall for WAN applications.