3.5.3
Internal circuits
Fig. 3.7:
Inputs and test pulses at an MSI 420 module
Fig. 3.8:
Outputs at an MSI 420/430 module
3.5.4
Limited short-circuit detection in the input circuits
Ä One MSI 4xx module has four test signal generators T1 – T4.
Ä Short-circuits between test signal generators of a MSI 4xx module are detected. Short circuit
detection is only ensured between different modules if the test gaps of the test signal gener-
ators are < 4 ms, the test periods ≥ 200 ms. Short-circuits past 24 V DC (after High) at in-
puts that are connected to test outputs are detected independently of the length of the test
gaps.
Make note of this during wiring (e.g. through separate routing or protected lines)!
Leuze electronic
WARNING
MSI 400
Product description
22