Safe zero-speed/slow-speed monitor

The Wieland SNS 4084K standstill monitor enables machinery operators in process industries to safely monitor two input signals in the 0.1 to 99 Hz frequency range.

The 45 mm housing fits into standard racks and operates on 24 VDC nominal (16.8 to 30 VDC) power. The unit provides four semiconductor outputs with automatic or manual start and can operate in the -25 to +55 °C temperature range.

The main function of the SNS 4084K standstill monitor is safe monitoring of the frequency of pulses on the inputs I1 and I2 of the device. If the frequency of the pulses is higher than the adjusted frequency (0.1 to 99 Hz), the outputs Q1/Q2 are switched off. This monitoring function is used for detecting a standstill or limited machine speed.

The signal can then be used to inch the machine at low speed or unlock solenoid locks at zero speed.

The sensors for monitoring the standstill can be, for example, two inductive proximity switches connected on I1, I2 (when I4 has a low level) or an incremental sensor with HTL outputs connected on I1 to I3 (when I4 has a high level).

The Wieland SNS 4084K housing and terminals are protected according to EN60529, IP40 and IP20. It complies with EN62061, EN ISO 13849-1 standards, with TÜV, cULus, approvals pending.