Technical Data of the Digital Inputs/Outputs if used as Inputs¶
| Parameter | Value | |
|---|---|---|
| Number of channels per module | Max. 16 digital inputs | |
| Reference potential for all inputs | Terminals 1.9…4.9 (minus pole of the process supply voltage, signal name ZP) | |
| Input current, per channel | Technical Data of the Digital Inputs DC551-CS31 - Digital Inputs and Output | |
| Input type acc. to EN 61131-2 | Type 1 | |
| Input delay (0->1 or 1->0) | Typ. 8 ms, configurable from 0.1 to 32 ms | |
| Input signal voltage | 24 VDC | |
| Signal 0 | -3 V…+5 V *) | |
| Undefined signal | > +5 V…< +15 V | |
| Signal 1 | +15 V…+30 V | |
| Ripple with signal 0 | within -3 V…+5 V *) | |
| Ripple with signal 1 | within +15 V…+30 V | |
| Max. cable length | ||
| Shielded | 1000 m | |
| Unshielded | 600 m | |
*) Due to the direct connection to the output, the demagnetizing varistor is also effective at the input (see figure) above. This is why the difference between UPx and the input signal may not exceed the clamp voltage of the varistor. The varistor limits the voltage to approx. 36 V. Following this, the input voltage must range from -12 V to +30 V when UPx = 24 V and from -6 V to +30 V when UPx = 30 V.