Voltage Monitoring - Siemens 6SL3845-2NN41-8AD2 Operating Instructions Manual

In order to be able to perform signal handling with great accuracy, the operational amplifiers
must satisfy the following criteria:
● Low noise: 2.8 nV/√Hz
● Large bandwidth: 10 MHz
● Low quiescent input curent: max. 12 nA
● Low offset voltage: max. 75 μV
The signals are relayed to the following interfaces:
● For diagnosis to the process data acquisition system (option G66).
● For alternative diagnosis with the aid of indicating instruments (option K21/K22).
● Via additional isolation amplifiers to the control station / I&C.
● For simplified diagnosis with an oscilloscope to measuring sockets X20 to X27.
Tasks of reference module AD586LR
The reference module installed on the DM10 diagnosis module supplies the reference voltage
for voltage subtraction of the eight analog signals. The reference voltage of 5 V is subtracted
from the input signal in the value range from 0 V to 10 V. The voltage supplied by the reference
element must meet demanding requirements in terms of signal accuracy.
The reference element must satisfy the following signal accuracy criteria:
● High linearity
● Low drift
● Voltage deviation of max. ±5 mV
The signal accuracy of the AD586LR reference element is within the permitted tolerance range
with a deviation tolerance of ±2.5 mV.
3.5.12.3

Voltage monitoring

Tasks of the comparators
The internal voltages are connected via connector -X34 and the external voltages via connector
-X35. These voltages are required for supplying the diagnosis module. At the same time these
voltages are monitored for undervoltage, and the logic signal state is visualized by one LED in
each case. If all the voltages being checked are within the standard range, another LED (H23)
signals "Power Supply OK". If the status of the power supply is signaled to the closed-loop
control system as "Power Supply Not OK", then the closed-loop control system intervenes and
shuts down the drive in a controlled manner to prevent damage to the drive.
SINAMICS SM150 6SL3845-2NN41-8AD2
Operating Instructions Rev.201910281310 EXAMPLE
3.5 Description of the components
Description
43