Program features 57
Mechanical brake control
A mechanical brake can be used for holding the motor and driven machinery at zero
speed when the drive is stopped, or not powered. The brake control logic observes
the settings of parameter group
external signals, and moves between the states presented in the diagram on page
. The tables below the state diagram detail the states and transitions. The timing
shows an example of a close-open-close sequence.
The mechanical brake control logic operates on a 10 ms time level.
Inputs of the brake control logic
The start command of the drive (bit 5 of
) is the main control
source of the brake control logic. An optional external open/close signal can be
selected by
. The two signals interact as follows:
• Start command = 1
AND
signal selected by
= 0
→ Request brake to
open
• Start command = 0
OR
= 1
→ Request brake to
close
Another external signal – for example, from a higher-level control system – can be
connected via parameter
to prevent the brake from opening.
Other signals that affect the state of the control logic are
• brake status acknowledgement (optional, defined by
• bit 2 of
(indicates whether the drive is ready to follow the
given reference or not),
• bit 6 of
(indicates whether the drive is modulating or
not),
• optional FSO-xx safety functions module.
Outputs of the brake control logic
The mechanical brake is to be controlled by bit 0 of parameter
. This bit should be selected as the source of a relay output (or a digital
input/output in output mode) which is then wired to the brake actuator through a relay.
See the wiring example on page
The brake control logic, in various states, will request the drive control logic to hold
the motor, increase the torque, or ramp down the speed. These requests are visible in
parameter
.
Settings
(page
).
Summary of Contents for ACS860
Page 1: ... ABB INDUSTRIAL DRIVES ACS860 primary control program Firmware manual ...
Page 4: ......
Page 10: ...10 Table of contents ...
Page 18: ...18 Using the control panel ...
Page 24: ...24 Control locations and operating modes ...
Page 54: ...54 Program features ...
Page 78: ...78 Program features ...
Page 90: ...90 Application macros ...
Page 342: ...342 Additional parameter data ...
Page 380: ...380 Fault tracing ...
Page 381: ...Fault tracing 381 ...
Page 382: ...382 Fault tracing ...
Page 436: ...436 Control chain diagrams ...
