CIMPLICITYFunctionality Differences Among Models
Not all Modicon programmable logic controllers behave/support the same function codes. The following table illustrates the differences:
| Function Type | Function Code | 184/384 | 484 | 584 | 984 | Quantum | VersaPoint ENIU | VersaMax ENIU |
| Read Coil Status | 1 | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Read Input Status | 2 | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Read Holding Reg. | 3 | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Read Input Reg. | 4 | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Force Single Coil. | 5 | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Force Single Hold Reg. | 6 | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Force Multiple Coil Reg. | 15 | Yes | No | Yes | Yes | Yes | No | No |
| Force Multiple Holding Reg. | 16 | Yes | No | Yes | Yes | Yes | Yes | Yes |
| Program General Reg. | 13 | Yes | No | Yes | Yes | Yes | No | No |
| Poll General Reg. | 14 | Yes | No | Yes | Yes | Yes | No | No |
