Operating Instructions
Chapter
12
DME5000
8009813/ZJV1/2017-05
© SICK AG • Germany • Subject to change without notice
119
Terms
12
Terms
12.1
PROFIBUS
®
All devices are connected in a bus structure (line). A segment can contain up to 32
components (master or slaves).
At the beginning and end of each segment, the bus is terminated by an active bus
terminator. Interference-free operation requires that the two bus terminators are
constantly supplied with power. The bus terminator of the DME is not internally
implemented. A supply voltage for the bus terminator is available at the bus output plug.
This 5 V supply voltage is galvanically sepa-rate from the DME supply voltage. The 5 V
supply voltage can be charged with 100 mA and may be used for optical coupling
modules.
Terminator for bus terminator: See section 9.2 "Accessories".
If there are more than 32 devices, repeaters must be used to connect the bus segments.
The max. cable length depends on the transmission speed; see table 2.
The indicated cable length can be increased by using repeaters. We recommend not using
more than 3 repeaters in series. The DME supports all transmission speeds listed in table
2 and automatically adjusts to the bus master baud rate when starting up.
Baud rate (Bit/s)
9.6 K
19.2 K
45.45 K
93.75 K
187.5 K
Range /Segment (m)
1200
1200
1200
1200
600
Baud rate (Bit/s)
500 K
1.5 M
3 M
6 M
12 M
Range /Segment (m)
200
200
100
100
100
12.2
RS-422
The RS-422 standard meets the requirements to quick, transfer-safe data transmission.
This interface is intended for serial data transfer in the full duplex procedure with a
transmission rate up to 10 MBaud and a cable length of 1000 m (DIN 66259, part 3).
The interface is operated with a data channel for transmission (T) and a data channel for
reception (R). The high transfer safety is achieved by assessment of the difference voltage
between each twisted-pair wire.
Tab. 2: Range depending on
transmission speed
