2-2
Section
Communication Unit PRT1-COM
16
–
This setting should always be changed to appropriate value.
–
Station addresses 126 and 127 are invalid and should not be used.
--
Do not use station address 0 in combination with the C200HW-PRM21
PROFIBUS-DP Master.
1. Asynchronous mode:
The MULTIPLE I/O Bus transmit/receive cycles are independent of the
messages being transmitted/received at the PROFIBUS-DP interface.
2. Synchronous mode:
A MULTIPLE I/O Bus transmit/receive cycle will only be initiated if new data
has been received at the PROFIBUS-DP interface.
More information can be found in: section 8-1-4.
Note
Synchronous mode has no meaning when only input MULTIPLE I/O Units are
attached. In this case the switch setting is ignored and asynchronous mode is
used.
The INTEL switch is used for selection of the little-endian/big-endian mode, to
define the transfer method for double-byte data transfer between
PROFIBUS-DP and MULTIPLE I/O Bus.
This allows for adjustment of the data format if required by the PROFIBUS-DP
master.
1. Big-endian mode (Often referred to as Motorola mode):
The first byte transmitted over PROFIBUS-DP is the most-significant byte
whereas the second byte is the least-significant byte.
MULTIPLE I/O Bus
PROFIBUS-DP message
2. Little-endian mode (Often referred to as Intel mode):
The first byte transmitted over PROFIBUS-DP is the least-significant byte
whereas the second byte is the most-significant byte.
MULTIPLE I/O Bus
PROFIBUS-DP message
Note
Changing the transfer method to ’Little-endian’ mode will also have impact on
the transfer of the status bytes, see also section 3-2-4.
Mount the Unit on DIN 35-mm rail using the DIN Track Mounting Hook.
The I/O Unit Bus connectors on the MULTIPLE I/O Units must be connected with
the appropriate cables to provide I/O Unit interface and allow power to be
supplied to the I/O Units.
An End connector cable must be connected to the right-side connector of the last
I/O Unit (terminator).
Data exchange method
Double byte transfer
method
Mounting
I/O Unit Bus Connectors
Содержание PRT1-COM
Страница 1: ...Cat No W900 E2 1 PROFIBUS DP MULTIPLE I O TERMINAL PRT1 COM GT1 Series ...
Страница 2: ...PRT1 COM GT1 Series PROFIBUS DP MULTIPLE I O TERMINAL Operation Manual Produced December 1999 ...
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Страница 187: ...Cat No W900 E2 1 Note Specifications subject to change without notice December 1999 Authorized Distributor ...