| I/O system | GRT1 I/O Bus |
| Type of module | Digital I/O |
| I/O connection type | Push-in |
| Connection method | 2-wire, 3-wire |
| Number of digital inputs | 4 |
| Digital input type | NPN |
| Permitted voltage at input | 15-26.4 V |
| Number of digital outputs | 0 |
| Digital output type | None |
| Output current | 0 A |
| Short-circuit protected outputs | |
| Number of IOV (V+) terminals | 4 |
| Number of IOG (V-) terminals | 4 |
| Degree of protection (IP) | IP20 |
| Height | 84 mm |
| Width | 15 mm |
| Depth | 74.4 mm |
| Weight | 108 g |