Allen-Bradley Rockwell Automation 857 User Manual page 214

7-8
Communications
Communication Protocols
(cont.)
857-UM001A-EN-P – July 2009
Table 7.6 – Profibus DP Parameters
Parameter Value
Mode
Cont
Reqst
bit/s 2400
Emode
Channel
(Limit60)
(NoLimit)
InBuf
OutBuf
Addr 1 – 247
Conv
–
VE
Set = An editable parameter (password needed)
Clr = Clearing to zero is possible
In continuous mode the size depends on the biggest configured data offset of a data item
to be send to the master. In request mode the size is 8 bytes.
In continuous mode the size depends on the biggest configured data offset of a data to be
read from the master. In request mode the size is 8 bytes.
When configuring the Profibus master system, the length of these buffers is needed. The
device calculates the lengths according the Profibus data and profile configuration, and the
values define the in/out module to be configured for the Profibus master.
If the value is "–", Profibus protocol has not been selected or the device has not restarted
after protocol change or there is a communication problem between the main CPU and the
Profibus ASIC.
Unit Description
Profile selection
Continuous mode
Request mode
bps Communication speed from the main
CPU to the Profibus converter. (The
actual Profibus bit rate is
automatically set by the Profibus
master and can be up to 12 Mbit/s.)
Event numbering style.
Use this for new installations.
(The other modes are for
compatibility with old systems.)
bytes Size of Profibus master's Rx buffer.
(data to the master)
bytes Size of Profibus master's Tx buffer.
(data from the master)
This address has to be unique within
the Profibus network system.
Converter type
No converter recognized
Converter type "VE" is recognized
Note
Set
(Set)
Set