ABB DSBC172 57310001-KD Bus Repeater Central Unit
Safety informationTo supply RLM 01, use only a safety-low voltage. This requirement also applies to
the alarm contact supply.
In accordance with the UL/CSA requirements an external protection (e.g. fuse) is
prescribed. The fuse rating can amounted to 1.6A to 10A (characteristic: medium
slow-acting or slow-acting). Protection of groups of several devices with a common
fuse is admissible (several RLM 01 or RLM 01 together with other devices).
When selecting a mounting location, make certain that the limit values for ambient
conditions specified in the technical data are observed and the module can discharge
heat without any obstruction.
Do not connect any bus lines that are laid partially or entirely outside buildings.
Voltage overload, for example resulting from lightning strikes, may destroy the
module. For protection against cases such as these, use optical fibre cable and
appropriate medium converters (electrical <==> optical) as high-quality electrical
isolation.
In accordance with the PROFIBUS installation guideline the shielding of the bus
cables are preferably connected at the start and at the end with earth potential. Place
the module on a low-resistance and low-inductance earthed DIN mounting rail.
Grounding measures by way of the E terminal (1) on the terminal strip are then not
required.
Front panel elements
Three Sub-D connectors A, B and M are located on the front panel of the RLM 01
for connection of the PROFIBUS cable. The 8-pin male multi-pin connector with
the associated terminal strip is used to connect the alarm and power supply wires.
There are also LEDs for activity/error display, a rotary switch for setting the
transmission rate and a reset button (activate transmission rate).

The module should preferably be attached vertically on a DIN mounting rail. To do
this, place the two rear-side clamps on the top edge of the mounting rail. Then press
lightly on the underside of the module until the clamps spread apart and the bottom
edge of the rail locks audibly into place. The mounting location should be selected
so that the RLM 01 can discharge heat arising from power loss without hindrance. A
The redundant PROFIBUS lines are connected to the two terminals A and B.
Terminal M is provided for the non-redundant PROFIBUS line. All three
PROFIBUS connections A, B and M are designed uniformly with 9-pin Sub-D
connectors (sockets). The pin assignment conforms to the PROFIBUS standard.
RLM 01 uses only pins 3+8 for data transfer and 6+5 for power supply to an
external resistor combination for bus termination. The following table shows the
maximum assignment for PROFIBUS usage.
Figure 4. Attachment to a DIN mounting rail
Pin: Short description: Meaning:
1 Shield Shield
2 -/- Not assigned