Connecting And Setting Up The Micromaster Series 4 Drive - Siemens Simatic S7-200 System Manual

Connecting and Setting Up the MicroMaster Series 4 Drive

Connecting the MicroMaster 4 Drive
To make the connection to the MicroMaster Series 4 (MM4) drive, insert the ends of the RS-485 cable into
the two caged clamp, screwless terminals provided for USS operation. The standard PROFIBUS cable
and connectors can be used to connect the S7-200.
Caution
Interconnecting equipment with different reference potentials can cause unwanted currents to flow
through the interconnecting cable.
These unwanted currents can cause communications errors or damage equipment.
Be sure all equipment that you are about to connect with a communications cable either shares a
common circuit reference or is isolated to prevent unwanted current flows.
The shield must be tied to chassis ground or pin 1 on the 9-pin connector. It is recommended that you
tie wiring terminal 2–0V on the MicroMaster drive to chassis ground.
As shown in Figure 11-6, the two wires at the
opposite end of the RS-485 cable must be
inserted into the MM4 drive terminal blocks. To
make the cable connection on a MM4 drive,
remove the drive cover(s) to access the terminal
blocks. See the MM4 user manual for details
about how to remove the covers(s) of your
specific drive.
The terminal block connections are labeled
numerically. Using a PROFIBUS connector on
the S7-200 side, connect the A terminal of the
cable to the drive terminal 15 (for an MM420) or
terminal 30 (MM440). Connect the B terminal of
the cable connector to terminal 14 (MM420) or
terminal 29 (MM440).
If the S7-200 is a terminating node in the network, or if the connection is point-to-point, it is necessary to
use terminals A1 and B1 (not A2 and B2) of the connector since they allow the termination settings to be
set (for example, with DP connector type 6ES7 972–0BA40–0X40).
Caution
Make sure the drive covers are replaced properly before supplying power to the unit.
If the drive is configured as the terminating node in the
network, then termination and bias resistors must be also be
wired to the appropriate terminal connections. For example,
Figure 11-7 shows an example of the connections
necessary for termination and bias for the MM4, model
6SE6420 drive.
Using the USS Protocol Library to Control a MicroMaster Drive
Figure 11-6 Connecting to the MM420 Terminal Block
Figure 11-7 Sample Termination and Bias
B (P) A (N)
14
120 ohm
15
1K ohm
1K ohm
2
1
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