Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE - Manual (Page 44)

5-26 DESCRIPTION OF OPERATION
1557-UM050F-EN-P – June 2013
Analog Outputs
A total of twelve programmable analog outputs is provided, six on each of the two Drive Control boards.
The analog outputs are 8-bit, non-isolated, with a range of -10V to +10V. The arrangement of analog
outputs is different for the original Drive Control boards 80165-018 and the new 18-Pulse Drive Control
boards 80190-118. For the original boards, four of the six analog outputs on each board are intended for
diagnostic purposes and are available at test points for connection to an oscilloscope or chart recorder.
The remaining two analog outputs on each board are intended for connection to external devices such as
meters or isolation modules, and are available at the analog I/O connector on each board. With the new
18-pulse boards, the analog outputs are split equally between three diagnostic outputs and three external
outputs. The allocation of the analog outputs is shown below:
No.
Output Control Board 80165-018 80190-118
1
Analog output 1L Line (lower) Test point AO1 Test point AO1
2 Analog output 2L Line (lower) Test point AO2 Test point AO2
3 Analog output 3L Line (lower) Test point AO3 Test point AO3
4 Analog output 4L Line (lower) Test point AO4 Connector J8
5 Analog output 1M Machine (upper) Test point AO1 Test point AO1
6 Analog output 2M Machine (upper) Test point AO2 Test point AO2
7 Analog output 3M Machine (upper) Test point AO3 Test point AO3
8 Analog output 4M Machine (upper) Test point AO4 Connector J8
9 Analog output 5L Line (lower) Connector J5 Connector J8
10 Analog output 6L Line (lower) Connector J5 Connector J8
11 Analog output 5M Machine (upper) Connector J5 Connector J8
12 Analog output 6M Machine (upper) Connector J5 Connector J8
Any parameter or variable can be assigned to any analog output, but it should be kept in mind that the
analog outputs on the two Drive Control Boards are serviced at different rates. The analog outputs on
each board are updated six times per cycle, which means that the line converter outputs are updated at a
fixed rate while the update rate for the machine converter varies with motor speed. The scaling of the
variables assigned to the analog outputs is given in the variable descriptions and cannot be changed.
However, the four or six external outputs are each provided with an adjustable offset and scale factor
which are applied after the predefined scaling to allow these outputs to be rescaled to suit the external
device they are driving.