All G120 control terminals are on the control unit (for example CU240E-2), not the power module. p0015 decides what each terminal does, so choose the macro first and then wire. Set analogue inputs with the DIP switch and p0756 together, and prove the wiring with r0722 (digital bits) and r0755 (analogue %).
- Macro first, wiring second.
- Toggle a switch and watch its bit in r0722.
- Keep external loads on the internal 24 V supply small.
- No 24 V on STO means no run.
The Terminal Strip at a Glance
A G120 is a power module (line and motor) plus a control unit (every control signal). A CU240B-2 has fewer I/O and no relay, so always use the diagram for your exact CU.
Choose the Macro First: How p0015 Decides What Each Terminal Does
No terminal has a fixed job. p0015 applies a ready-made set of BICO links during quick commissioning. Pick the macro that fits, wire to it, and only then change single terminals.
| p0015 | Interface pattern |
|---|---|
| 1 | Two fixed speeds |
| 3 | Four fixed speeds |
| 12 | Two-wire control, analogue setpoint on AI 0 |
| 17 / 18 | Two-wire control, methods 2 and 3 |
| 19 / 20 | Three-wire control, methods 1 and 2 |
| 21 | Fieldbus USS |
Macro availability varies by control unit, so check the list for yours.
Digital Inputs and the Sink/Source Decision
The DI COM link sets the direction. Source (PNP) is the usual choice and matches most PLC outputs.
Wire a real drive, then prove it works
Hands-on SINAMICS G120 terminal wiring, macro selection and verification on live hardware — Pune or online.
Analogue Inputs and Outputs
Each AI is set in two places that must agree: the DIP switch (hardware) and p0756 (firmware). The analogue outputs usually carry actual speed or current to a meter or PLC.
| Signal | DIP switch | p0756 | Note |
|---|---|---|---|
| 0–10 V | U (voltage) | 0 | Simple, but noise-sensitive |
| 0–20 mA | I (current) | 2 | No wire-break detection |
| 4–20 mA | I (current) | 3 (monitored) | Preferred: broken wire = fault |
Digital Outputs, the Relay and Safe Torque Off
Assign outputs with p0730 (DO 0), p0731 (DO 1) and p0732 (DO 2) to a status bit, for example fault active r0052.3, operation enabled r0052.2 or alarm r0052.7.
EPLAN Wiring Diagram: Complete G120 Panel, Step by Step
Here is the whole panel on a two-sheet EPLAN-style schematic following wiring best practice: IEC 60204-1 isolation and wire colours, an EMC-correct motor cable, a PELV 24 V supply, screened analogue lines, wired protection inputs and two-channel STO. Step through it or let it play; the circuit being explained is highlighted.
- Isolate and protectA lockable main switch -Q0 (IEC 60204-1) isolates the panel. -Q1 uses the breaker or fuse type and rating given in the PM240-2 manual, not a guess.
- Power module and earthingUse a filtered PM240-2 (Class A) or the line filter or reactor the manual specifies. Drive leakage current is above 3.5 mA, so the PE needs at least 10 mm² Cu or a second PE conductor.
- Motor cable and EMCUse a screened symmetrical cable with the PE conductor inside, running from the drive PE to the motor PE. Clamp the shield 360° at both ends. Keep power cables at least 20 cm from signal cables, crossing at 90°.
- Braking resistorKeep the resistor leads short and twisted or screened. Wire its thermal contact back to DI3 (/2.3) so an overheated resistor trips the drive.
- 24 V PELV supply-F2 feeds PSU -G1. L+ is fused by -F3, and M is bonded to PE at one point only. CU terminals 31/32 get external 24 V so the drive stays online with the mains off.
- Commons and field terminalsTake DI COM1, DI COM2 and GND to M. Feed the inputs from fused L+ instead of term 9 so everything shares one reference. Route field wires through numbered terminals -X1.
- Command inputs (macro 12)-S1 → DI0 ON/OFF1, -S2 → DI1 reverse, -S3 → DI2 acknowledge. Prove each with r0722 before commissioning.
- Speed setpoint, screenedRun pot -R2 on screened cable -W2 with the shield clamped on the CU shield plate. Link AI0− (4) to GND (2). Set the DIP switch to U and p0756 = 0.
- Protection inputsMotor PTC on T1/T2 (14/15) uses its own screened cable -W3 (p0601). The braking-resistor contact on DI3 is external fault p2106 = 722.3, low-active so a broken wire also trips.
- OutputsAO0 → meter -P1. Relay DO0 (20 → 19) switches fused L+ to lamp -H1 (p0730 = r0052.3). Stay within the relay contact rating, and prefer signalling a PLC input.
- Safe Torque OffTwo-channel E-stop -S0 and reset -S4 go into safety relay -K10. Its two outputs feed DI4/DI5 (F-DI0), with DI COM2 → M. Commission and test STO as the Safety Integrated manual requires.
Device list (EPLAN parts report)
| Tag | Device | Function / best-practice note |
|---|---|---|
| -Q0 | Main switch, lockable | Isolation for maintenance (IEC 60204-1) |
| -Q1 | Breaker / fuses | Type and rating from PM240-2 manual |
| -L1 | Line reactor (if required) | Harmonics / mains protection |
| -U1 | PM240-2 (filtered) + CU240E-2 | Frequency converter |
| -W1 | Screened symmetrical motor cable | 360° shield both ends, PE inside the cable |
| -M1 | Induction motor + PTC | Δ/Y per plate, PTC to CU 14/15 |
| -R1 | Braking resistor + thermal contact | Contact to DI3 as external fault |
| -F2 / -G1 / -F3 | MCB, 24 V PSU, L+ fuse | PELV, M bonded to PE once |
| -X1 | Field terminal strip | Numbered terminals for every field wire |
| -S1 / -S2 / -S3 | Selector, selector, pushbutton | ON/OFF1, reverse, acknowledge |
| -R2 / -W2 | Pot + screened cable | Speed setpoint, shield on CU plate |
| -P1 / -H1 | Meter / lamp | Actual speed, fault indication |
| -S0 / -S4 / -K10 | 2-ch E-stop, reset, safety relay | STO on F-DI0 (DI4/DI5) |
Terminal wiring list (EPLAN terminal diagram)
| From | To CU240E-2 terminal | Signal | Check with |
|---|---|---|---|
| L+ (-F3) | 31 | +24 V supply in | CU powers up |
| M | 32, 28, 69, 34 | 0 V / commons | — |
| L+ → -S1 → X1:1 | 5 (DI0) | ON/OFF1 | r0722.0 |
| L+ → -S2 → X1:2 | 6 (DI1) | Reverse | r0722.1 |
| L+ → -S3 → X1:3 | 7 (DI2) | Acknowledge | r0722.2 |
| L+ → -R1:T → X1:4 | 8 (DI3) | Ext. fault, p2106 = 722.3 | r0722.3 = 1 when OK |
| -R2 via -W2 | 1, 3, 2 (+ link 4–2) | Speed setpoint | r0755 |
| -M1 PTC via -W3 | 14, 15 | Motor temperature (p0601) | r0035 |
| 12 / 13 | -P1 | Actual speed 0–10 V | meter reading |
| L+ → 20 → 19 | -H1 | Fault relay (p0730) | provoke a fault |
| -K10 14 / 24 | 16 (DI4), 17 (DI5) | STO F-DI0 | drive enables |
Wiring best-practice checklist
| Best practice | Why |
|---|---|
| Separate power and signal cables (≥ 20 cm, separate ducts, cross at 90°) | Stops PWM noise coupling into the I/O |
| Screened motor cable, shield clamped 360° at both ends | Keeps high-frequency current off the panel and away from other equipment |
| PE conductor inside the motor cable; PE ≥ 10 mm² Cu at the drive | Drive leakage current is above 3.5 mA |
| Screened analogue and PTC cables, shield on the CU shield plate | Stable setpoint and temperature readings |
| Fused 24 V PELV, M bonded to PE once, CU on external 24 V | One reference, no ground loops, diagnostics with mains off |
| Protection contacts wired low-active (NC) | A broken wire trips instead of hiding a fault |
| Field wires via numbered terminals with ferrules and wire numbers | Faster fault-finding and clean handover |
| Two-channel STO through a safety relay, tested at commissioning | Required safety integrity; a single channel is not enough |
Training example for a CU240E-2 with macro 12 and source wiring. Wire colours follow common IEC 60204-1 panel practice; use your plant standard if it differs. Size -Q1, the cables and -R1 from the PM240-2 hardware manual, and design the STO circuit to your machine’s risk assessment.
Reading Terminal State from Parameters
Two read-only parameters turn wiring checks into a two-minute job. If a bit or a value does not move, the fault is in the wiring, the common, the DIP switch or p0756, not in the drive setup.
Hands-On Lab: Wire and Verify Every Terminal
Hands-on- A G120 with a CU240E-2 or similar on a training rig, safely isolated for wiring.
- Toggle switches, a 10 kΩ potentiometer and the terminal diagram for your CU. Estimated time: 45 minutes.
Identify the control unit
Read the CU type from its label and find its exact terminal diagram.
Choose the macro
Decide the p0015 macro and note what each terminal will do.
Wire inputs for source
With the drive isolated, link DI COM to 0 V and wire switches from 24 V into DI 0–2.
Prove with r0722
Power up, display r0722, and toggle each switch.
Wire the potentiometer
Wire it across 10 V and 0 V with the wiper on AI 0. Set the DIP switch to U and p0756 = 0.
Sweep r0755
Turn the potentiometer through its full range.
Assign and test the relay
Set p0730 to fault active, provoke a fault, then acknowledge it.
Every DI moves its bit in r0722, the AI sweeps the full range in r0755, and the relay follows the fault state. Wiring is now off the suspect list.
Frequently asked questions
How do I wire a SINAMICS G120 drive panel?
Isolate with a lockable main switch, then feed the PM240-2 power module through a circuit breaker (and an optional line reactor), and run screened symmetrical motor cable with the PE inside and the shield clamped 360° at both ends, kept at least 20 cm from signal cables. Supply the CU240E-2 with fused PELV 24 V on terminals 31/32. Wire the inputs through numbered terminals to match the p0015 macro, for example DI0 ON/OFF1, DI1 reverse, DI2 acknowledge and AI0 speed potentiometer. Use screened cable for the potentiometer and motor PTC (terminals 14/15), wire the braking-resistor thermal contact to DI3, use relay DO0 for the fault lamp, and wire two-channel STO through a safety relay to DI4/DI5. Check the inputs with r0722 and r0755.
Where are the control terminals on a SINAMICS G120?
On the control unit, not the power module. The power module carries only line and motor connections. A CU240E-2 provides six digital inputs, two analogue inputs, two analogue outputs, relay and transistor outputs, internal 10 V and 24 V supplies and the Safe Torque Off inputs.
Why did my terminal functions change by themselves?
The macro parameter p0015 was changed. A macro reassigns every digital and analogue terminal in one step by rewriting the BICO interconnections. Choose the macro first, then wire to match it.
What is the difference between sink and source wiring?
In source (PNP) wiring, DI COM is linked to 0 V and an input is active when 24 V is applied. In sink (NPN) wiring, DI COM is linked to 24 V and an input is active when pulled to 0 V. Inputs sharing a common must all use the same mode.
Why does my analogue input read nothing?
Usually the DIP switch and p0756 disagree with the signal, for example a 4–20 mA sensor on an input still set to voltage. Set the DIP switch to current and p0756 = 3 for monitored 4–20 mA, then check r0755.
How do I check whether my digital input wiring is correct?
Display r0722, which shows each digital input as a bit, and toggle the switch. If the bit does not follow, the fault is in the wiring, the common or the supply, not in the parameters.
Why won't my G120 run even though there is no wiring fault?
Check the Safe Torque Off inputs. If the fail-safe input does not have 24 V, the drive blocks its output pulses and the motor produces no torque.
Should I use 0–10 V or 4–20 mA for the speed reference?
Prefer 4–20 mA. Current loops resist drive-panel noise much better, and the live zero means a broken wire reads 0 mA and can be trapped as a fault, while a broken 0–10 V wire reads as a valid zero-speed command.