Rockwell Automation DAG6.5.8 APPLICATION GUIDE SCADA SYSTEM - Manual (Page 59)

Publication AG-UM008C-EN-P - February 2005
Configuring Enhanced PLC-5 Processors 2-21
Table 2.6 Configuring the PLC-5 Processor as a Device on a Point-to-Point Link
RSLogix 5 Tab Parameter Selections
Channel 0 Diagnostic File Select an unused integer file that you want to use to store channel status information. You
must define a diagnostic file in order to be able to view channel 0 status. See Table 2.7 on
page 2-22 for a description of what this file contains.
Remote Mode Change Enable remote mode change if you want to switch the configuration of the channel during
runtime. Leave the parameter set at the default if you are not using remote mode change.
Mode Attention
Character Select a character that will signal a remote mode change. Leave the parameter set at the
default if you are not using remote mode change.
System Mode Character Select a character that will signal the channel to switch into system mode. Leave the
parameter set at the default if you are not using remote mode change.
User Mode Character Select a character that will signal the channel to switch into user mode. Leave the
parameter set at the default if you are not using remote mode change.
Serial Port Baud Rate Select a communication rate that all devices in your system support. Configure all devices
in the system for the same communication rate.
Bits Per Character Match the number of bits per character to the device with which you are communicating.
Stop Bits Match the number of stop bits to the device with which you are communicating.
Control Line This parameter defines the mode in which the driver operates. Choose a method
appropriate for your system’s configuration:
•
If you are not using a modem, choose NO HANDSHAKING.
•
If you are using a full-duplex modem, choose FULL-DUPLEX.
Parity Parity provides additional message packet error detection. To implement even parity
checking, choose Even. To implement no parity checking, choose None.
Options NAK Receive Define the number of NAKs the processor can receive in response to a transmitted message
before the station declares the message undeliverable.
DF1 ENQs Define the number of enquiries (ENQs) that you want the processor to send after an ACK
timeout occurs before the station declares the message undeliverable.
ACK Timeout Define the amount of time, in 20 millisecond increments, you want the processor to wait for
an acknowledgment from a station to its transmitted message.
Options Detect Duplicate
Messages Duplicate Packet Detection lets the PLC-5 processor detect if it has received a message that
is a duplicate of its most recent message from another station. If you choose detect
duplicate messages, the processor will acknowledge (ACK) the message but will not act on
it since it has already performed the message’s task when it received the command from
the first message.
If you want to detect duplicate packets and discard them, check this parameter. If you want
to accept duplicate packets, and execute them, leave this parameter unchecked.
MSG Application
Timeout Define the number of 30 second increments within which the reply message must be
received before the error bit is set on the message. The timer starts when the ladder
program first initiates the message and is restarted if/when the ACK is received.
Error Detect With this selection you choose how the processor checks the accuracy of each DF1 packet
transmission.
BCC: This algorithm provides a medium level of data security. It cannot detect:
•
transposition of bytes during transmission of a packet
•
the insertion or deletion of data values of zero within a packet
CRC: This algorithm provides a higher level of data security.
Select an error detection method that all devices in your system support.
When possible, choose CRC.
Important: The station address in the point-to-point driver is determined by the DH+ address defined by switch assembly S1.