DSZY35 Hall Sensor Wiring to S7-1200 HSC: Configuration Guide

Overview

The Drive System Europe DSZY35 stainless-steel linear actuator with HS2 dual-channel Hall sensors provides incremental position feedback that must be decoded by a high-speed counter (HSC) on a Siemens SIMATIC S7-1200 CPU. The HS2 suffix designates two Hall-effect channels (Data 1 and Data 2) producing quadrature signals — the only configuration that lets the PLC determine both displacement and direction of travel. This reference covers the electrical interface, TIA Portal HSC configuration, input filter tuning, verification, and field diagnostics required to bring the actuator online reliably on CPU 1211C, 1212C, 1214C, 1215C, 1217C, or an S7-1200 G2 successor.

DSZY35 Actuator Electrical Interface

The DSZY35 ships as a single cable harness carrying motor power leads and the HS2 Hall sensor leads. Always refer to the DSZY35 datasheet (PDF) for the exact wire color mapping of your specific variant (DSZY35-24-19-400-HS2-IP69K, 10070612).

HS2 designates a two-channel quadrature Hall sensor. The pulse count per millimetre of stroke depends on the actuator lead and internal gearing — consult the datasheet for the pulses-per-revolution figure and convert to pulses-per-millimetre using the actuator's lead.

Wiring Topology

The topology below shows the recommended connection between the DSZY35 and the S7-1200 onboard inputs used by HSC_1. The 24 V sensor supply on the PLC must be sized for the DSZY35 inrush; add flyback or PTC protection per the actuator datasheet.

S7-1200 HSC Hardware Prerequisites

The S7-1200 CPU exposes six high-speed counter instances on the onboard digital inputs. The table below shows the default Phase A / Phase B / Reset mapping for HSC_1 through HSC_6 on a standard CPU 12xx with no signal board. With a Signal Board (SB) installed, the affected HSC inputs can be reassigned to SB terminals.

Verify the mapping for your CPU in the device manual — S7-1200 G2 (firmware 5.x) added additional HSC inputs and re-mapped some legacy assignments. Refer to the Siemens S7-1200 HSC application examples for canonical wiring patterns.

TIA Portal HSC Configuration Step-by-Step

1. Open the project in TIA Portal V16 or later (V18+ recommended for firmware 4.4 CPUs).
2. In the project tree, double-click Device configuration for the S7-1200 CPU.
3. Expand Properties → High-speed counters (HSC) in the inspector window.
4. Select the HSC to use — HSC_1 is the conventional choice for I0.0/I0.1.
5. Check Enable this high-speed counter.
6. Set the Counter type to Quadrature (A/B phase). Do not select "Pulse and direction" — that mode treats Data 1 as count and Data 2 as direction, which wastes one of the quadrature edges.
7. Select the Counting mode: 1x, 2x, or 4x evaluation. 4x gives the highest resolution (four counts per electrical cycle) at the cost of doubled maximum frequency requirements.
8. Open the channel properties for I0.0 and I0.1 and set the digital input filter to the fastest available value (see filter table below).
9. Optional: assign a hardware reset input. With a DSZY35, a hardware reset is rarely needed because the actuator's stroke is mechanically limited.
10. Click Compile → Hardware (rebuild all).
11. Download the hardware configuration to the CPU.
12. Download the software (program blocks) — both hardware and software downloads are required for HSC changes to take effect.

Input Filter Time Constant — The Most Common Field Issue

The default digital input filter on S7-1200 standard inputs is in the millisecond range. The DSZY35 Hall sensors produce pulses with periods well below one millisecond at typical actuator speeds. Leaving the filter at default suppresses every transition and the HSC will not increment. The symptom is exactly what field engineers report: "both inputs are on but the counter does not count."

Set the I0.0 and I0.1 filter to the fastest available value. After downloading hardware and software, the HSC will register transitions.

Quadrature Decoding Theory

Two Hall channels arranged 90° electrically out of phase produce the quadrature pattern shown below. The HSC hardware in the S7-1200 decodes direction from the phase relationship: if A leads B, the counter increments; if B leads A, the counter decrements. Without both channels connected, direction cannot be resolved.

In 1x evaluation, the counter increments on a single edge of A. In 4x evaluation, it increments on every edge of A and B (four counts per electrical cycle). Choose 4x unless the resulting count rate exceeds the HSC maximum frequency limit.

Pulse Rate Calculation

Verify that the HSC can keep up with the DSZY35 Hall sensor by calculating the expected pulse frequency at the actuator's maximum speed. The formula depends on the actuator's mechanical lead (mm per motor revolution) and the internal pulses-per-revolution figure of the HS2 Hall sensor:

Example calculation: if the DSZY35 has a lead of 4 mm/rev and the HS2 outputs 100 pulses per motor revolution, then at a maximum linear speed of 50 mm/s:

This is well within the S7-1200 HSC capability, even with the default filter setting. However, if your actuator has a faster lead (e.g. 1 mm/rev) and runs at 200 mm/s, the pulse rate jumps to 20 kHz — far above the millisecond filter cutoff. Always confirm the pulse rate from the DSZY35 datasheet and choose the filter accordingly. The maximum input frequency of the HSC filter f_max must satisfy f_pulse ≤ f_max.

S7-1200 HSC Counting Mode Selection

The DSZY35 HS2 typically produces pulses in the tens to low-hundreds of Hz at rated actuator speed. Any of the three evaluation modes will work; 4x gives the best position resolution.

Verification Procedure

1. Place the CPU in RUN mode.
2. Open an online watch table and force the DSZY35 motor direction output to extend.
3. Monitor the HSC_1 count value. The default address for the HSC_1 count is ID1000 (input double word, 32-bit signed). Watch this ID in the watch table — it should increment while extending and decrement while retracting.
4. If ID1000 updates erratically or not at all, return to the filter configuration step.
5. If the count increments in the wrong direction relative to your process, swap Data 1 and Data 2 wires at the PLC terminals — no software change needed.
6. Move the actuator to a known mechanical reference position (e.g. fully retracted) and use CTRL_HSC to set the counter to zero.
7. Command a known stroke length and compare the count delta against the calculated pulses-per-millimetre figure.

Sample SCL Code

The HSC_1 hardware instance is auto-generated by TIA Portal once the HSC is enabled in the device configuration. You can read and control it directly from user logic via the CTRL_HSC instruction. The simplest pattern for a homed linear actuator is:

"DB_HSC".HSCInstance := 1;
"DB_HSC".NewCountValue := 0;            // home position
"DB_HSC".CmdEnable := TRUE;
CTRL_HSC(Instance := "HSC_1",        // hardware instance from device config
         NewCountValue := "DB_HSC".NewCountValue,
         Enable := "DB_HSC".CmdEnable);

// Read current count
"DB_HSC".CurrentCount := "HSC_1".CountValue;

The HSC count is also directly accessible as ID1000 (HSC_1) / ID1004 (HSC_2) / ID1008 (HSC_3) / ID1012 (HSC_4) / ID1016 (HSC_5) / ID1020 (HSC_6) without invoking CTRL_HSC, provided the HSC is enabled in the device configuration.

Homing Routines

The DSZY35 has mechanically limited end positions but no built-in home reference. Implementing a homing sequence ensures the HSC count starts at zero from a known mechanical position:

1. Command the actuator to retract until a hard mechanical stop is reached (use a current limit or time-out in the motor drive).
2. Use CTRL_HSC to set the HSC count to 0 — the mechanical hard-stop is now your reference.
3. Move the actuator to the operating position; the count now represents absolute position in pulses from the home.

For absolute homing with sub-millimetre accuracy, add an external proximity sensor on the actuator rod and use it as the HSC reset input (I0.3 for HSC_1, etc.). Wire the proximity sensor PNP output into I0.3 and enable the hardware reset in the HSC configuration. The HSC will auto-zero on every rising edge of I0.3.

Using HSC as Encoder Input to a TO Axis

If you need closed-loop positioning, configure a Siemens technology object positioning axis (TO_PositioningAxis) and assign the HSC as the encoder input. This adds:

• Automatic homing sequences
• Software limit switches
• Positioning profiles
• Trajectory planning with jerk limiting

The TO configuration requires the same HSC hardware setup as described above. The HSC then feeds pulses into the axis controller instead of being read directly in user logic. Note that a TO positioning axis typically requires a pulse generator output on the CPU side as well; with a simple DSZY35 direction-control actuator the TO is often overkill — a basic HSC plus manual direction control in user logic is sufficient.

HMI Tag Mapping

To display the actuator position on a Siemens HMI (Basic Panel, Comfort Panel, or Unified), expose the HSC count to the HMI tags:

Configure the HMI tag with linear scaling: HSC raw count (pulses) ÷ pulses-per-mm = millimetres. The pulses-per-mm value comes from the DSZY35 datasheet lead and the Hall sensor PPR.

Firmware Compatibility

Diagnostic Buffer & Status Bits

When the HSC is misbehaving, the CPU diagnostic buffer typically reports an entry such as "Error in high-speed counter" or "Channel fault". Check Online & Diagnostics → Diagnostics buffer first. The HSC also exposes status bits in the process image:

These mappings are CPU-firmware-specific; cross-reference the S7-1200 System Manual for your firmware version.

EMC and Cabling Best Practices

The DSZY35 actuator cable carries both motor power and low-level Hall signals. Long cable runs in industrial cabinets are prone to capacitive coupling between the motor phases and the Hall outputs. To minimize noise pickup on the HSC inputs:

• Use the supplied shielded cable where possible; do not extend with unshielded wire.
• Ground the shield at the PLC cabinet entry only — do not ground at the actuator end.
• Route the actuator cable at least 100 mm away from VFD output cables and any 24 V switching power supply lines.
• If the cable must be extended, use twisted-pair shielded cable with the Data 1 and Data 2 wires twisted together.
• Add a 10 kΩ pull-up resistor from each Hall output to +24 V at the PLC terminal strip if the open-collector rise time is too slow for the HSC.

Safety Considerations

• Always wire the DSZY35 motor direction outputs through safety-rated relays or motor contactors with E-stop in series.
• Never rely on the HSC count alone for end-of-travel protection — add mechanical limit switches at both ends of stroke.
• If the actuator is in a personnel-accessible area, the entire safety function must comply with ISO 13849-1 PL d or higher; use a Siemens F-CPU for safety-rated position monitoring.
• The DSZY35 is rated IP69K — verify that cable glands and conduit entries preserve the same rating after installation.

Alternative Controllers

The DSZY35 HS2 quadrature output can be decoded by any controller with a quadrature counter:

• Allen-Bradley MicroLogix 1400 HSC inputs
• Allen-Bradley CompactLogix with high-speed counter module (5069-HSC)
• Beckhoff EL5101 incremental encoder input
• WAGO 750-637 counter module
• IDEC FT1A SmartAXIS with HSC input

The same filter-setting principle applies: configure the digital input filter to the fastest value the platform allows. The millisecond default that catches most S7-1200 users is the same trap on other platforms.

Troubleshooting Matrix

Field Commissioning Checklist

1. Verify actuator 24 V supply polarity at the cable entry before applying power.
2. Power up PLC and confirm the 24 V sensor supply LED is on.
3. In TIA Portal, enable HSC_1, set quadrature mode, set 4x evaluation.
4. Set I0.0 and I0.1 input filter to fastest available value.
5. Download hardware, then software.
6. Open watch table, monitor ID1000 (HSC_1 count) and the I0.0 / I0.1 process image.
7. Force the motor direction output; verify ID1000 changes monotonically.
8. Reverse direction; verify ID1000 reverses.
9. If direction is wrong, swap Data 1 / Data 2 at the PLC terminal.
10. Run a full-stroke extend / retract cycle and record the count delta; compare against calculated pulses-per-mm.
11. Home the actuator (set count to 0 at fully retracted).
12. Save the project; archive the TIA Portal backup to the maintenance folder.

FAQ