Publication 1766-RM001A-EN-P - October 2008
592
Protocol Configuration
DF1 Full-Duplex
Protocol
DF1 Full-Duplex protocol provides a point-to-point connection between
two devices. DF1 Full-Duplex protocol combines data transparency
(American National Standards Institute ANSI - X3.28-1976 specification
subcategory D1) and 2-way simultaneous transmission with embedded
responses (subcategory F1).
The MicroLogix controllers support the DF1 Full-Duplex protocol via
RS-232 connection to external devices, such as computers, or other
controllers that support DF1 Full-Duplex.
DF1 is an open protocol. Refer to
DF1 Protocol and Command Set
Reference Manual
, Allen-Bradley publication 1770-6.5.16, for more
information.
DF1 Full-Duplex Operation
DF1 Full-Duplex protocol (also referred to as DF1 point-to-point protocol)
is useful where RS-232 point-to-point communication is required. This
type of protocol supports simultaneous transmissions between two
devices in both directions. DF1 protocol controls message flow, detects
and signals errors, and retries if errors are detected.
When the system driver is DF1 Full-Duplex, the following parameters can
be changed:
DF1 Full-Duplex Configuration Parameters
(All MicroLogix 1400 Controller)
Parameter
Options
Programming Software
Default
Channel
MicroLogix 1400: Channel 0
0
Driver
DF1 Full Duplex
DF1 Full Duplex
Baud Rate
300, 600, 1200, 2400, 4800, 9600, 19.2K, 38.4K
19.2K
Parity
none, even
none
Source ID (Node Address)
0…254 decimal
1
Control Line
no handshaking, Full-Duplex modem
no handshaking
Error Detection
CRC, BCC
CRC
Embedded Responses
auto detect, enabled
auto detect
Duplicate Packet (Message) Detect
enabled, disabled
enabled
ACK Timeout (x20 ms)
1…65535 counts (20 ms increments)
50 counts
NAK retries
0…255
3 retries
ENQ retries
0…255
3 retries
Stop Bits
not a setting, always 1
1
efesotomasyon.com - Allen Bradley,Rockwell,plc,servo,drive