Help converting system from S7 300 to S7 1500

Hi everyone,

as the title says i'm converting a plant from S7 300 to S7 1500, the problem i'm facing is about a control techniques inverter that seems to be used with a certain logic to check if an arm reaches the desired position.

The problem is that the inverter gives me a few digital inputs about the state of the movement of the arm, and the "movement complete" signal is never 1 so the application doesn't proceed.

The strangest thing is that with the S7 300 everything works, so my question is, how do i check the logic of the inverter and/or the parameters i give to the inverter itself ( in order to let him do his logic i guess ? )

To such inverter i also give outputs, like to run the motor and so, and even with the output ON to run the motor, nothing moves...

Hopefully you can help me

Thank you!

Hello JacopoPodavini,

I don´t know if this can help you: Migration Guide: SIMATIC S7-300/400 to SIMATIC S7-1500

Have you verified the wiring differences between the S7-300 and the S7-1500 digital output modules are properly handled?  For example, let's suppose the s7-300 DO module common was actually set to 24V, the DO would be toggling the common, but if the s7-1500 DO was wired so DC common was 0V (the more widely used approach), things will behave very differently than expected.

Not saying you designed it wrong, but it is possible it was not wired as required by S7-1500 DO module schematic drawing(s).

Verify the wiring - using a watch table to force signals to trigger drive outputs (with the VFD high voltage disabled - by CB or FU.  Using the watch table, you can trigger VFD DO's, measure them at the terminals of the PLC DO module(s) and at the VFD terminals, and also inside the drive control software to verify signals are reaching the proper drive model values.

Are you using Siemens VFDs (with PB/PN), or generic VFDs with classic / legacy digital & analog control and feedback?

JacopoPodavini

Hi everyone,

as the title says i'm converting a plant from S7 300 to S7 1500, the problem i'm facing is about a control techniques inverter that seems to be used with a certain logic to check if an arm reaches the desired position.

The problem is that the inverter gives me a few digital inputs about the state of the movement of the arm, and the "movement complete" signal is never 1 so the application doesn't proceed.

The strangest thing is that with the S7 300 everything works, so my question is, how do i check the logic of the inverter and/or the parameters i give to the inverter itself ( in order to let him do his logic i guess ? )

To such inverter i also give outputs, like to run the motor and so, and even with the output ON to run the motor, nothing moves...

Hopefully you can help me

Thank you!

Thank you for your time and answer.

Turns out the inverter lost a few parameters including the one where it allows the control of the motor by the control word.

The strange thing was infact that i was receiveing everything (like the encorder position and so on) but couldnt make it move, that explains it.

Thank you everyone !