SINAMICS V90 Telegram 111 vs 7/9 with SINA_POS and DriveLib

Overview

The SINAMICS V90 servo drive family supports PROFINET-based cyclic communication using a fixed set of standard telegrams defined in the PROFIdrive profile. When paired with a SIMATIC controller (S7-1200, S7-1500, ET 200SP CPU), engineers typically reach for the SINA_POS function block from the SINAMICS STEP 7 Toolbox or the SINAMICS blocks within the SINAMICS DriveLib library to execute jog, homing, MDI (Manual Data Input) absolute/relative positioning, and traversing block moves.

A common integration pitfall is the assumption that any positioning telegram will work transparently with SINA_POS. Field experience shows that only Telegram 111 (and to a limited extent Telegram 110) carries the full set of position-control process data required by SINA_POS, including POS_STW1 and POS_STW2. Telegrams 7 and 9, although superficially "positioning" telegrams, omit those two control words and therefore cannot drive MDI absolute/relative moves or reference-point approach when used with SINA_POS in its default configuration.

This reference documents the underlying telegram structures, identifies the root cause of the failure modes, and provides the recommended path using DriveLib blocks for telegrams 7, 9, 110, 2, and 370.

V90 Telegram Architecture and PROFIdrive Compliance

The SINAMICS V90 PN (PROFINET variant) implements standard PROFIdrive telegrams as defined in IEC 61800-7-204. Each telegram is a fixed-length, fixed-structure container of process data words (PZD). Both directions are independently defined:

• PZD OUT (setpoint): Controller → Drive (control words + setpoints)
• PZD IN (actual value): Drive → Controller (status words + actual values)

The telegrams supported on V90 PN, per the V90 operating instructions, are summarized below.

Telegram Structure Comparison (7, 9, 110, 111)

The structural difference between Telegram 7/9 and Telegram 110/111 is the root cause of the integration problem with SINA_POS. Telegrams 7 and 9 contain only the general PROFIdrive state machine words (STW1, STW2) and basic setpoints; they do not carry the position-specific control words POS_STW1 and POS_STW2 that the basic positioner (EPOS) in the V90 requires for MDI modes, jogging modes, homing mode selection, and traversing block control.

SINA_POS Block and Why It Requires Telegram 111

The SINA_POS block is a parameterized function block that abstracts PROFIdrive signaling for EPOS (Basic Positioner) operation on SINAMICS drives. It encapsulates the bit-level manipulation of the following process-data words:

• STW1 — general drive state machine (ON/OFF1, OFF2, OFF3, enable, ramp-function generator, setpoint enable, fault acknowledge)
• STW2 — supplementary control (DSC enable, controller enable, etc.)
• POS_STW1 — positioning-specific control (traversing block selection, MDI mode, jog signals, referencing)
• POS_STW2 — extended positioning control (signal source for jog/referencing, setpoint direction, MDI absolute/relative)
• STW (POS basic) — EPOS operating mode (jog, MDI, homing, traversing block)

When SINA_POS is configured for Telegram 111, the block exchanges all of the above words. When the user changes the drive to Telegram 7 or 9, those POS_STW1 and POS_STW2 words simply do not exist on the wire. The HMI/STEP 7 input fields for "Operating mode," "Traversing block," "Position," "Velocity override," and "MDImode" write into words the drive never receives, leading to:

• Jog and traversing block modes appear to work because those are triggered by combinations of bits in STW1/STW that are present in all telegrams.
• Absolute and relative MDI moves silently fail because they require POS_STW1 bits 0–4 (MDI mode selection and type: absolute/relative) and POS_STW2 bit 4 (direction positive/negative, MDI setpoint acceptance edge).
• Reference-point approach fails because the "Set reference point" / "Start referencing" trigger is encoded in POS_STW2 and not in STW2.

POS_STW1 and POS_STW2 Bit Definitions

Per the SINAMICS S120/S210 List Manual (entry ID 109763271, page 2109 and following), the bit fields of the two position control words are defined as follows.

DriveLib Library as the Alternative for Telegram 7 / 9 / 110 / 2 / 370

For applications where the application profile (e.g., positioning by external controller computing position loops) requires Telegram 7 or 9, or where torque-limited positioning (Telegram 370) is used, Siemens recommends the SINAMICS DriveLib block library for TIA Portal. DriveLib (entry ID 109475044) provides FB/FC blocks for each supported telegram, exposing the raw PZD slots so the application can manage every bit directly.

DriveLib blocks handle PROFIsafe/PROFIdrive state machine compliance (per the PROFIdrive profile V4.2) and provide typed I/O for each PZD slot. The user constructs the application logic by either:

1. Writing a custom application layer that bit-packs the positioning control word (POS_STW1 / POS_STW2) even when the drive is configured for Telegram 7 or 9 — not recommended, because the data is not transmitted over PROFINET.
2. Reverting to Telegram 110/111 and using the dedicated DriveLib block (recommended), which exposes POS_STW1 and POS_STW2 as direct I/O.
3. Using Telegram 7/9 for external-controller position loops (drive in "speed control with encoder feedback" mode) and computing trajectory in the S7 PLC, then using NSOLL_B as the speed setpoint. This is not basic positioner (EPOS) mode; it is an open PROFINET speed profile.

Step-by-Step: Switching V90 to Telegram 111 for SINA_POS

1. Open the V90 project in TIA Portal and select the V90 PN device in the project tree.
2. Navigate to Device View → PROFINET interface → Telegram configuration. Add Telegram 111 in slot 0 / 1 as required. Remove any other telegram; only one standard telegram may be active at a time.
3. Open the drive's parameter view (STARTER/SINAMICS Startdrive) and set p0922 = 111 (standard telegram 111). Save to ROM.
4. Power-cycle the drive if p0922 is changed at runtime, or perform a "Copy RAM to ROM" then a restart for online change to take effect.
5. Insert SINA_POS from the SINAMICS blocks library in your S7 program. Wire the HW identifier, IO data, and enable inputs per the block's data sheet.
6. Compile and download the S7 project. Go online and observe status word bits; ZSW1.0 (Ready to switch on), ZSW1.1 (Ready), ZSW1.2 (Operation enabled) must all be 1 before motion is permitted.
7. Test jog first (ModeSelect = 0 or 1). Confirm axis moves in both directions.
8. Test homing (ModeSelect = 6). Confirm reference point is reached and ZSW2.4 (referenced) = 1 after completion.
9. Test MDI absolute and relative (ModeSelect = 5). Write Position, Velocity, MDImode inputs and pulse the Execute input.
10. Test traversing blocks (ModeSelect = 7). Configure blocks in V90 parameters p26xxx and select the active block via the TraversingBlock input.

Verification Checklist

Troubleshooting Matrix

DriveLib Implementation Notes (Telegram 7 / 9 Path)

If for engineering reasons the application must remain on Telegram 7 or 9 (e.g., controller computes the closed position loop and only sends speed/acceleration profiles to the drive), the implementation pattern with DriveLib is as follows:

1. Import SINAMICS DriveLib V15.0 or later into TIA Portal from the Siemens support page.
2. Place the LAcycCtrl_7 or LAcycCtrl_9 FB in the cyclic OB (e.g., OB1 or OB91 with the configured send clock).
3. Drive the input STW1 using a standard PROFIdrive state-machine FB or write each bit manually:

   // PROFIdrive state machine bits — STW1 (PZD1 OUT)
   STW1_ON_OFF1   := TRUE;   // Bit 0
   STW1_OFF2      := TRUE;   // Bit 1 — negated: TRUE = no OFF2
   STW1_OFF3      := TRUE;   // Bit 2 — negated: TRUE = no OFF3
   STW1_INHIBIT   := FALSE;  // Bit 3 — pulse enable
   STW1_HLG       := FALSE;  // Bit 4 — ramp-function generator enable
   STW1_RFG_STOP  := FALSE;  // Bit 5 — ramp stop
   STW1_SETPOINT  := TRUE;   // Bit 6 — setpoint enable
   STW1_ACK       := FALSE;  // Bit 7 — fault acknowledge (rising edge)
   

4. Drive the NSOLL_B (PZD3–4 OUT) with the speed setpoint computed by your controller's position loop. Standardize units to 0x4000 0000 = 100 % rated speed per PROFIdrive profile.
5. Read back ZSW1 and ZIST_B (PZD3–4 IN) for status monitoring and actual speed feedback.
6. Implement the position loop in S7: compute position error → speed command, applying Kv (loop gain), feed-forward, and any velocity/acceleration limits.

Cross-Reference to SINAMICS Documentation

The official reference for the telegram structure is the SINAMICS S120/S150 List Manual (entry ID 109763271). Specifically:

• Page 2074: Telegram 7 and Telegram 9 structure diagrams
• Page 2076: Telegram 110 and Telegram 111 structure diagrams
• Page 2109f: Bit-level definitions of POS_STW1 and POS_STW2 (and the matching status words POS_ZSW1, POS_ZSW2)

The SINAMICS DriveLib entry (ID 109475044) contains download links for the TIA Portal library, example projects for each supported telegram, and documentation of the FB/FC inputs.

Frequently Asked Questions