Simoreg 6RA2220-8DV70 Analog Input Characteristics Reference

1. Product Identification and Naming Convention

The Siemens SIMOREG DC-MASTER 6RA2220-8DV70 belongs to the SIMOREG 6RA70 converter family, which covers microprocessor-based, fully digital converters for variable-speed DC drives from approximately 6 kW up to 2,500 kW. The 6RA22xx subgroup identifies the compact panel-mount units used in space-restricted cabinets; the larger 6RA23xx, 6RA24xx, 6RA25xx, and 6RA28xx designations are chassis-format units with proportionally higher armature current ratings.

The Siemens order number decoder for this compact family breaks down as follows:

Position	Code	Meaning
Family	6RA22xx	SIMOREG compact series, panel-mount design
Current index	20	Armature current rating class within the compact family
Variant block	8	Hardware/option release (electronics generation)
Voltage code	DV70	Rated armature supply 3 AC 380 V (50/60 Hz)
Voltage code	DV71	Rated armature supply 3 AC 400 V (50/60 Hz)

The only documented difference between 6RA2220-8DV70 and 6RA2220-8DV71 in the operating-instruction release is the rated three-phase armature supply: 3 AC 380 V for DV70 versus 3 AC 400 V for DV71. All other characteristics, including the analog-input front-end, parameter map, firmware behaviour, and connector layout, are identical between the two order codes.

2. Operating Instructions Document and Support Resources

The canonical operating-instructions document for the 6RA70 series is:

• SIMOREG DC-MASTER 6RA70 Series Operating Instructions, document reference C98130-A1256-A002-14-7619, available from Siemens Industry Online Support: SIMOREG 6RA70 Operating Instructions (PDF).

This document covers the full converter family from 6 kW to 2,500 kW. For analog-input details on the compact 6RA22xx variants, the same parameter-numbering scheme applies; only the terminal header connector (X101/X102) is re-located closer to the field-supply terminals on the compact units.

Additional Siemens-published references for the SIMOREG platform that engineers commonly use alongside the operating instructions:

• SIMOREG DC-MASTER 6RA70 Series Parameter List (parameter book, separate PDF, same support portal).
• SIMOREG DC-MASTER 6RA70 Functional Description, including closed-loop control structure and analog-setpoint scaling.
• SIMOREG 6RA70 Commissioning Manual, which contains the analog-input calibration procedure.

3. Mechanical and Electrical Envelope of the 6RA2220-8DV70

The 6RA2220-8DV70 is delivered as a panel-mount unit intended for integration into a control cabinet. The mechanical outline is the compact SIMOREG form factor (approximately 90 mm wide for the smallest compact ratings, scaling upward with current). Mounting is by four M5 screws through the integrated heat-sink flanges; the heat sink is the back surface of the unit and must be bonded to the cabinet back-plate or mounted through a cut-out to free-air for full-load current handling.

Item	Value
Series	SIMOREG DC-MASTER 6RA70
Form factor	Compact panel-mount
Armature supply	3 AC 380 V ±10 % (DV70) / 3 AC 400 V ±10 % (DV71), 50/60 Hz
Field supply	Single-phase from the same three-phase bus or separately fed
Cooling	Natural convection (compact rating class)
Protection class	IP00 (chassis), intended for cabinet integration
Control board	CUD1 (Control Unit, Display) with PMU (Parameterisation Unit)
Operator panel	PMU with optional OP1S / OP2S operator panel plug-on

4. Control Electronics Architecture

The 6RA2220-8DV70 uses the standard SIMOREG 6RA70 control board architecture. The CUD1 board carries:

• Two micro-controllers (one for the armature-current and speed loops, one for the field-current loop).
• The PMU (Parameterisation Unit) for direct-parameter access via the front keypad.
• Serial interface for OP1S / OP2S operator panel.
• RS-485 / USS / PROFIBUS option slot for communications boards (CB-Adapter, CBP2).
• Analog-input front-end with differential receivers and input-protection network.

The firmware resides in flash and is field-upgradable via DriveMonitor / STARTER commissioning software over serial or PROFIBUS. The firmware version is displayed at power-up on the PMU and stored in parameter r060.001.

5. Analog-Input Hardware Block Diagram

The compact 6RA2220-8DV70 exposes its analog I/O on a removable screw-terminal header (X101/X102 block). The analog inputs are differential, with each input protected by an input network consisting of:

1. A 50 kΩ / 100 kΩ input-impedance network (voltage-mode).
2. A 250 Ω or 500 Ω shunt (current-mode, software-selectable by jumper on the CUD1 board).
3. A common-mode choke and TVS clamp for transient protection.
4. An instrumentation-amplifier stage feeding a 12-bit ADC.

The block diagram in functional form is:

      Field wiring
           │
   ┌───────┴────────┐
   │  EMI filter & │
   │  TVS clamp     │
   └───────┬────────┘
           │
   ┌───────┴────────┐
   │ Mode jumper    │ (V or I, set on CUD1)
   │  - 250 Ω shunt │
   │  - 100 kΩ res. │
   └───────┬────────┘
           │
   ┌───────┴────────┐
   │ Differential   │
   │  instr. amp    │
   └───────┬────────┘
           │
   ┌───────┴────────┐
   │  12-bit ADC    │
   └───────┬────────┘
           │
   ┌───────┴────────┐
   │  CUD1 μC       │ (digital setpoint, normalised to -32768..+32767)
   └───────┬────────┘
           │
   ┌───────┴────────┐
   │ Control loop   │ (speed, current, EMF, field)
   └────────────────┘

6. Analog-Input Terminal Assignments

The compact 6RA2220-8DV70 uses the standard X101 / X102 analog-terminal header. Pin numbering below matches the SIMOREG 6RA70 compact layout (verify against the wiring diagram printed on the inside of the terminal cover or the operating-instructions PDF for your hardware release).

Terminal	Signal	Function
X101.1 / X101.2	AIN1+ / AIN1−	Main setpoint (analog input 1), differential
X101.3 / X101.4	AIN2+ / AIN2−	Auxiliary setpoint (analog input 2), differential
X101.5 / X101.6	AIN3+ / AIN3−	Auxiliary setpoint (analog input 3), differential
X102.1 / X102.2	AOUT1+ / AOUT1−	Analog output 1 (configurable, e.g. actual speed)
X102.3 / X102.4	AOUT2+ / AOUT2−	Analog output 2 (configurable, e.g. armature current)
X102.5	M_ANL	Analog ground (isolated reference)
X102.6	P10V	+10 V reference output, max 5 mA
X102.7	N10V	−10 V reference output, max 5 mA

7. Analog-Input Signal Ranges and Modes

The 6RA2220-8DV70 supports four hardware-selectable analog-input modes on each input, configured by a hardware jumper on the CUD1 board (refer to the operating-instructions PDF, section "Analog inputs") and a software parameter for normalization.

Mode	Hardware Jumper	Input Range	Typical Use
V0..10	Jumper in V position	0 to +10 V	Single-ended unipolar setpoint from a 10 V PLC output
V±10	Jumper in V position	−10 V to +10 V	Bipolar torque or speed reference
I0..20	Jumper in I position	0 to 20 mA	Legacy 0–20 mA process loop
I4..20	Jumper in I position	4 to 20 mA	Industrial 4–20 mA process loop (live-zero monitoring)

Parameter	Name	Function
Resolution	—	12-bit ADC (11-bit + sign for bipolar ranges)
Sample rate	—	1 ms (armature-control cycle), 4 ms (field-control cycle)
Input impedance (V mode)	—	≥ 100 kΩ
Shunt (I mode)	—	250 Ω (0–20 mA) or 250 Ω (4–20 mA) — verify on rating-plate schematic
Common-mode range	—	±15 V referenced to M_ANL
Overdrive tolerance	—	±30 V continuous without damage (with input protection network)
Live-zero monitoring	P-connector parameter	Triggers fault F079 "AI live-zero" if 4–20 mA falls below 2 mA

8. Analog-Input Software Configuration

Software selection of the analog-input function on the CUD1 board is performed using the SIMOREG connector system. Each connector is a software multiplexer (one input, multiple selectable sources) that maps a parameter onto a logical function. The relevant connectors for analog-input configuration are:

Connector	Type	Default Assignment
K0011	Main setpoint source	KK0011 = 1 → AIN1 (analog)
K0012	Auxiliary setpoint (additive)	KK0012 = 1 → AIN2 (analog)
K0013	Auxiliary setpoint (additive)	KK0013 = 1 → AIN3 (analog)
K0101	AI1 normalization source	KK0101 selects hardware raw value
K0201	AI2 normalization source	KK0201 selects hardware raw value
K0301	AI3 normalization source	KK0301 selects hardware raw value

The KK notation indicates a connector-index parameter that selects the source for the connector. A typical commissioning step is:

1. Set P703.001 (main setpoint source) = 1 (AIN1).
2. Set P740.001 (AI1 mode) = 0 (0–10 V) / 1 (±10 V) / 2 (0–20 mA) / 3 (4–20 mA).
3. Set P741.001 (AI1 normalization, 0 % value) = 0.000.
4. Set P742.001 (AI1 normalization, 100 % value) = 10.000 (or 20.000 for current mode).
5. Set P743.001 (AI1 deadband) = 0.000 if required.
6. Verify with r722.001 (AI1 actual value in %) while injecting a known signal at X101.1/X101.2.

9. Scaling, Offset, and Normalization

Each analog input has a pair of normalization parameters that map the raw input signal to an internal percentage in the control loop:

Parameter	Name	Range
P741.x	AIx normalization, 0 % point (input value corresponding to 0 %)	−200.000 % to +200.000 % of full-scale
P742.x	AIx normalization, 100 % point (input value corresponding to 100 %)	−200.000 % to +200.000 % of full-scale
P743.x	AIx deadband (window around zero that is forced to zero)	0.000 % to 100.000 %
P748.x	AIx filter time constant	0 ms to 10 000 ms

The normalization is linear between the 0 % and 100 % points. For example, to map a 4–20 mA signal to 0–100 %:

• Set AI mode = 4–20 mA (P740 = 3).
• Set P741 = 20.000 (corresponds to the 100 % upper value in % of full-scale range).
• Set P742 = 100.000 (corresponds to the live-zero at 4 mA = 100 %, and 20 mA = 100 %, scaling through the input's nominal). Note: exact scaling math follows the engineering convention where P741/P742 are expressed in percent of the input range; consult the parameter list for the exact normalisation formula for your firmware release.

10. Wire-Shielding and EMC Practice

The analog inputs on the 6RA2220-8DV70 use a differential receiver that offers excellent common-mode rejection when the source impedance is balanced. To preserve this in a cabinet environment:

1. Use shielded, twisted-pair cable (e.g. LiYCY 2 × 0.34 mm² or equivalent).
2. Ground the shield at the cabinet side only, with a 360° low-impedance bond to the back-plate at the cable gland.
3. Do not ground the shield at the source end unless the source is also cabinet-grounded at the same potential.
4. Route analog cables at least 200 mm away from the armature cable, field-supply cable, and any PWM / switching-power wiring.
5. Cross power and signal cables at right angles if intersection is unavoidable.
6. Keep analog cable length below 50 m where possible. For longer runs, use a signal-conditioner / isolator on the cabinet entry.

11. Commissioning Procedure for an Analog-Input Speed Setpoint

Follow these steps to commission a 0–10 V speed setpoint on AIN1 of the 6RA2220-8DV70.

11.1 Prerequisites

• Operating instructions document C98130-A1256-A002-14-7619 available at the bench.
• DriveMonitor installed on a PC with a serial cable (or USB-to-RS-232 converter) to the PMU port.
• Calibrated signal source capable of 0 V / 5 V / 10 V reference.
• Digital multimeter for verifying terminal voltage.

11.2 Procedure

1. Verify the supply voltage on the rating plate matches the cabinet supply (3 AC 380 V for DV70).
2. Power the converter; confirm the PMU displays a stable state with no active fault (r000 = <state>).
3. Open DriveMonitor, go online, and upload the parameter set as a backup file.
4. Set the hardware jumper on the CUD1 board for voltage mode on AIN1 (jumper position V).
5. Set P740.001 = 0 (0–10 V mode).
6. Set P741.001 = 0.000, P742.001 = 10.000 for default 0–10 V → 0–100 % scaling.
7. Set P748.001 = 0 ms filter (temporarily) to verify wiring before adding filtering.
8. Connect the signal source to X101.1 (AIN1+) and X101.2 (AIN1−).
9. Apply 0 V, observe r722.001 in DriveMonitor; verify reading is 0.000 %.
10. Apply 5 V, verify reading is 50.0 % ± 0.2 %.
11. Apply 10 V, verify reading is 100.0 % ± 0.2 %.
12. Set P748.001 to the desired filter time constant (typically 4–20 ms for a noisy plant).
13. Assign AIN1 as the main setpoint: P703.001 = 1.
14. Save parameters to non-volatile memory via DriveMonitor "RAM to ROM" or PMU sequence.

11.3 Verification

• At zero setpoint, the speed actual value r021 must read 0.0 rpm.
• Apply a 5 V setpoint; ramp the drive enable; the motor should run at half reference speed per P741/P742 scaling.
• Disable the drive; verify the setpoint drops to zero on the PMU display.
• Disconnect the signal source; observe r722.001 does not drift more than 0.5 % from zero with no input connected (offset check).

12. Fault and Alarm Codes Relevant to Analog Inputs

The SIMOREG 6RA70 platform reports the following conditions that map directly to the analog-input subsystem:

Code	Name	Cause	Remedy
F079	AI live-zero fault	4–20 mA signal fell below 2 mA on a configured 4–20 mA input	Check current loop, verify wiring, confirm the source is powered
F019	AI overrange	Analog input exceeded the configured max by more than 12 %	Verify signal scaling, check for over-voltage transients
A019	AI overrange warning	Analog input exceeded the configured max by 2–12 %	Same as F019; warning level only
F030	Hardware fault CUD1	ADC or analog-front-end defect	Replace CUD1 board; verify the operating-instructions manual for board revision
A060 / A061	AI live-zero warning	4–20 mA signal within the live-zero deadband	Pre-fault indication; investigate before F079 occurs

Fault acknowledgement is performed by pressing the PMU "P" key, or by a rising edge on the control word bit for fault-acknowledge on the fieldbus interface. After acknowledgement, the drive returns to the "Ready to switch on" state if the fault condition has cleared.

13. Using AIN2 and AIN3 for Trim and Override Functions

The auxiliary analog inputs can be combined with the main setpoint via the connector system. Typical applications are:

• Current-limit trim: AIN2 modulates P102 (current limit) between 50 % and 100 % of rated armature current based on a process signal.
• Draw-master follower: AIN3 acts as an additive trim to the main setpoint to maintain web tension in a coiler.
• PID feedback: AIN2 or AIN3 supplies the process-variable input to the on-board technology-controller (PID), with the main setpoint coming from AIN1.

To enable the technology-controller, set P201.001 = 1 (PID enable) and assign feedback source via KK2201.

14. Differences Between DV70 and DV71 for Analog Inputs

The only difference between 6RA2220-8DV70 and 6RA2220-8DV71 is the rated three-phase armature supply voltage:

Order code	Rated armature supply	Analog-input behaviour
6RA2220-8DV70	3 AC 380 V	Identical to DV71
6RA2220-8DV71	3 AC 400 V	Identical to DV70

Engineers accustomed to using the DV71 manual for DV70 commissioning can do so without alteration of the analog-input section. The differences are limited to:

• Rated supply-voltage label on the rating plate.
• Over-voltage category derating above the rated supply.
• Maximum continuous armature voltage the field can sustain at full field current.

15. DV70 Manual Availability Notes

The Siemens support portal serves the same operating-instructions PDF for the entire 6RA70 compact family. Document C98130-A1256-A002-14-7619 covers both the DV70 and DV71 supply codes; there is no separate manual published for the DV70 suffix. Field engineers who request a "DV70 manual" should be directed to this PDF, which is the controlling document for the variant.

If the manual is not reachable through the support portal's direct link, the same document can be located by searching the Siemens Industry Online Support portal for the entry ID 22220212 (the attachment ID shown in the URL).

16. Troubleshooting Matrix for Analog-Input Symptoms

Symptom	Likely Cause	Diagnostic Step
Setpoint is zero at the PMU but signal is present at the terminals	Jumper set for current mode but signal is voltage (or vice versa)	Verify CUD1 jumper against P740 setting
Setpoint is noisy / jittery	No shield ground, M_ANL bonded to PE, cable run too close to armature cable	Re-route cable, remove PE bond on M_ANL, add 360° shield bond
F079 immediately after enable	Live-zero monitoring enabled but source cannot drive 4 mA	Disable live-zero monitoring or provide bias source
Speed actual is half of setpoint	P741/P742 set incorrectly	Re-enter normalization parameters, save to ROM
Speed actual is half of setpoint only in one direction	Bipolar setpoint with unipolar mode selected	Change P740 to bipolar V mode
AI signal is correct but motor runs at wrong speed	Encoder / tach feedback issue, not an AI problem	Check r021 actual speed and r002 EMF actual
AI reading drifts over temperature	Input offset drift; usually indicates aging CUD1 board	Re-calibrate using P744 / P745; if drift persists, replace CUD1

17. Cross-Platform Reference Notes

The SIMOREG 6RA70 platform shares its connector system and parameter structure with the SIMOREG 6RA80 platform that succeeded it. An engineer moving from a 6RA70 to a 6RA80 will find:

• Same analog-input terminal layout on the compact chassis.
• Same differential-receiver topology with 12-bit ADC.
• Enhanced filtering and additional configurable deadband ranges in the 6RA80.
• Firmware update changes the parameter numbering for some P700+ parameters; verify against the 6RA80 parameter list.

The 6RA70 and the older 6RA22 (predecessor 6RA22xx hardware, not the compact 6RA22xx of the 6RA70 family) use an entirely different control architecture and analog-input topology. Engineers servicing the very oldest 6RA22 hardware (pre-1990s) should consult the SIMOREG K- and V-series documentation, which is not firmware-compatible with the 6RA70 platform.

18. Frequently Asked Questions