IIR Filter disable on 1S drive

Summary/Issue Description

When using Omron’s 1S EtherCAT drive in Cyclic Synchronous Position (CSP) mode, the position IIR filter can be used when the communications cycle is 250 μs or more and is enabled by default.

Root Cause

This is a two degree of freedom mode (referenced as TDF in the 1S-series EtherCAT® Communications User’s Manual) and is not recommended for multi-axis path-based applications, as it introduces too much smoothing and delay. When the communications cycle is 125 μs, the position command filter is disabled by firmware.

Solution

This is controlled by the CoE object 3011h (section 9-2-5 in the 1S User’s Manual):

You can disable this filter with PMAC’s “ecattypedsdo()” function (as referenced in the “Power PMAC Software Reference Manual”):

Code as in the following can be used:

#define READ 1

#define WRITE 0

#define disable 0

#define enable 1

local slaveIndex = {slave index value}

local rwMode = WRITE

local readValue

//write “disable” (0) to index $3011-03.

readValue = ecattypedsdo(0,slaveIndex,rwMode,$3011,$3,disable,4)

Date/Revision History

First review 12/9/2025 V1.0

Author:

Ex. Stephen Milici, Technical Support Specialist"

References

Power PMAC Software Reference Manual:

https://assets.omron.com/m/76e3f5e50c46e0e9/original/Power-PMAC-Software-Reference-Manual.pdf

1S-series EtherCAT® Communications User’s Manual:

https://assets.omron.com/m/0bd037057bb5adc1/original/1S-Series-EtherCAT-Communications-User-Manual.pdf