Rockwell Automation DAG6.5.8 APPLICATION GUIDE SCADA SYSTEM - Manual (Page 51)

Publication AG-UM008C-EN-P - February 2005
Configuring Enhanced PLC-5 Processors 2-13
Serial Port Control Line This parameter defines the mode in which the master driver operates. Choose a method
appropriate for your system’s configuration:
•
If you are not using a modem, choose NO HANDSHAKING.
•
If the master modem is full duplex and the slave modem is full-duplex, choose
FULL-DUPLEX MODEM.
•
If all the modems in the system are half-duplex, choose HALF-DUPLEX MODEM
WITHOUT CONTINUOUS CARRIER.
Parity Parity provides additional message packet error detection. To implement even parity
checking, choose Even. To implement no parity checking, choose None.
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.
Options Station Address Define the octal address of the processor on the DF1 half-duplex link. Each station on a
link must have a unique address. Choose an address between 0 and 376
8
.
Station address 377
8
is the broadcast address, which you cannot select as a station’s
individual address.
DF1 Retries Define the number of times a master station retries either a message before the master
station declares the message undeliverable, or a poll packet to an active station before
the master station declares the station to be inactive.
RTS Send Delay RTS send delay is the amount of time, in 20 millisecond increments, that elapses
between the assertion of the RTS signal and the beginning of the message transmission.
This time allows the modem to prepare to transmit the message. The Clear to Send (CTS)
signal must be high for transmission to occur.
RTS Off Delay RTS off delay is the amount of time, in 20 millisecond increments, that elapses between
the end of the message transmission and the de-assertion of the RTS signal. This time
delay is a buffer to ensure that the modem has transmitted the message but should
normally be left at zero.
ACK Timeout Define the amount of time, in 20 millisecond increments, that you want the processor to
wait for an acknowledgment from a slave station to its transmitted message before
retrying. This timeout value is also used for the poll response timeout.
Reply Message Wait Define the amount of time, in 20 millisecond increments, that the master station will wait
after receiving an ACK (to a master-initiated message) before polling the slave station for
a reply.
Choose a time that is, at minimum, equal to the longest time that a slave station needs to
format a reply packet. This is typically the maximum scan time of the slave station.
MSG Application
Timeout The application timeout of the message is 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 ACK is received.
RSLogix 5 Tab Parameter Selections