RTA A-NDC Series - User Manual

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R.T.A. s.r.l. - Via E. Mattei – Fraz. Divisa 27020 Marcignago (PV) – Tel. +39.0382.929.855 - Fax +39.0382.929.150 – http://www.rta.it

[...] UL

Some parts of the text between square brackets are the original definition of UL

standard rules.

These requirements are mandatory for the models of this manual that are UL

compliant. These models can be identified by UL mark in the identificatio

n label

on the specific model.

In any case, we advise to comply with these requirements even for non-

certified models.

WARNING: It is user RESPONSIBILITY to check that this manual refers to product model and

version that will be used.

1) GENERAL CHARACTERISTICS

A-NDC 04

NDC 04.V

A-NDC 06

NDC 06.V

A-NDC 94

A-NDC 96

NDC 96.S

nom

(V)

from 24 to 85 from 24 to 85 from 24 to 85 from 24 to 85

min

(A)

0.65 1.9 0.65 1.9

max

(A)

2 6 2 6

Dimension

(mm)

93.5 × 101 × 25 110 × 108 × 34

Operati

ng temperature

from + 5°C to + 45°C (see point 7)

Table 1

nom Nominal value of DC voltage supply (range) at which the drive can operate without stabilized

supply.

Nominal phase current (peak value) which flow in each motor winding, measurable with motor

turning at low speed. This current can be selected by user among eight different values using

DIP-SWITCHES. Automatic current reduction at motor standstill is 50% of value set using DIP-

SWITCHES.

min and max Minimum and maximum value of nominal phase current setting.

2) LOGIC INPUT AND OUTPUT SIGNALS (connectors AM3 or C2, see Fig. 1, 7, 9 and 10)

All inputs and outputs are optically insulated (mutually and respect to internal power circuit). For all inputs and outputs you

have both positive and negative terminal.

Driving an input with a slow signal (i.e. relays) or with variable delay (i.e. PLC output) can give precision problem

or, worse, make the board do not work at all. If you have this type of signal, contact R.T.A.

2(-) ; 3(+) CURRENT OFF INPUT: When this signal is ON drive is active. When it is OFF drive is inhibited, thus motor

current (and so holding torque) is turned to zero. With jumper CO this input is always ON (drive is always

active).

4(-) ; 5(+) DIRECTION INPUT: With this signal ON motor rotation direction is opposite to the one obtained with input

OFF. This signal has to be valid at least 20 µsec. before STEP signal and has to stay in this state for at least

20 µsec. after last step sent to the drive.

6(-) ; 7(+) STEP INPUT: Step is performed on ON-OFF transition of this signal. Suggested duty-cycle: 50%. Max.

frequency: 300 KHz

(1)

with square wave signal supplied from a source with voltage between 3.5 and 13 Volt

(or a nominal voltage of 24 Volt for A-NDC96.S). In any case STEP signal half period has to be higher than

1.5 µsec.

(1)

NOTE: Max. frequency = 100 KHz with B and D type current profiles (400, 800 and 1600 steps/rev).

Max. frequency = 200 KHz with B and D type current profiles (3200 steps/rev).

Max. frequency = 300 KHz with B and D type current profiles (6400 and 12800 steps/rev).

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The R.T.A. A-NDC Series Stepping Motor Drives are Basic Drive Modules (BDM) designed for integration into more complex machinery or installations. These drives are specifically intended for use with two-phase stepping motors, featuring a base step angle of 1.8 degrees and a phase inductance between 1.0 and 12.0 mH. Use with other types of motors is not permitted.

Function Description:

The A-NDC series drives control stepping motors by converting step and direction signals into precise motor movements. They offer eight selectable nominal phase current values, configurable via DIP-SWITCHES, and automatically reduce current by 50% at motor standstill to minimize heat and power consumption. The drives include optical insulation for all logic inputs and outputs, ensuring protection from internal power circuits. They also feature a DRIVER FAULT OUTPUT that indicates when the drive is in a non-working state due to protection activation, automatically recovering once the protection resets. An INTERNAL GND terminal is provided for connecting the shield of logic signal cables.

Important Technical Specifications:

Models: A-NDC 04, A-NDC 04.V, A-NDC 06, A-NDC 06.V, A-NDC 94, A-NDC 96, A-NDC 96.S.
Nominal DC Voltage Supply (VDC nom): Operates from 24 to 85 Volts.
Nominal Phase Current (INP):
- A-NDC 04 / A-NDC 94: Minimum 0.65 A, Maximum 2 A.
- A-NDC 06 / A-NDC 96: Minimum 1.9 A, Maximum 6 A.
- Current values are configurable via DIP switches (Dip 1, 2, 3) with specific settings for each model, ranging from 0.65 A to 2.0 A for A-NDC 04/94 and 1.9 A to 6.0 A for A-NDC 06/96.
Dimensions:
- A-NDC 04 / A-NDC 06: 93.5 x 101 x 25 mm.
- A-NDC 94 / A-NDC 96: 110 x 108 x 34 mm.
Operating Temperature: +5°C to +45°C.
Max. Step Frequency:
- 100 KHz with B and D type current profiles (400, 800, 1600 steps/rev).
- 200 KHz with B and D type current profiles (3200 steps/rev).
- 300 KHz with B and D type current profiles (6400, 12800 steps/rev).
- STEP signal half period must be higher than 1.5 µsec.
Logic Input Signals:
- CURRENT OFF INPUT (2(-); 3(+)): Activates the drive when ON, inhibits it when OFF (motor current turned to zero). Jumper CO can force this input to ON (drive always active).
- DIRECTION INPUT (4(-); 5(+)): Reverses motor rotation direction when ON. Must be valid at least 20 µsec before and after STEP signal.
- STEP INPUT (6(-); 7(+)): Performs a step on ON-OFF transition. Suggested duty-cycle: 50%. Input voltage between 3.5 and 13 Volt (or 24 Volt for A-NDC96.S).
Logic Output Signals:
- DRIVER FAULT OUTPUT (8(-); 9(+)): SHORTED when working, OPEN when in no-working state. Vmax = 45 Volt, Imax = 50 mA, Vsat ≤0.8 Volt. A protection diode in parallel with the load is recommended for inductive loads.
Power Inputs and Outputs:
- 11: Power supply positive pole (+ VDC nom).
- 12: Power supply negative pole (- VDC nom).
- 13: GROUND (connect to Protective Earth terminal (PE)).
- 14-17: Motor winding terminals (B-, B, A-, A).
- 18: Connection point for shield of motor shielded cable.
Capacitor C: ≥ 10.000 µF for VDC = 24 Volt; ≥ 4.700 µF for VDC = 85 Volt. Must be near AM2 or C1 connector; max cable length = 1 meter.
Transformer Power: 100 to 450 VA, depending on drive model, current setting, motor model, motor speed, and duty-cycle.
Fuses:
- F1: Time lag, nominal current according to transformer power.
- F2: LP-CC-8 by COOPER BUSSMAN LCC or equivalent. Mandatory for UL compliance.
Maximum Motor Cable Length: 20 meters; section according to phase current RMS value.
Protection Degree:
- IP00 for A-NDC 04, A-NDC 04.V, A-NDC 06, A-NDC 06.V (requires protective enclosure).
- IP20 for A-NDC 94, A-NDC 96, A-NDC 96.S (requires protective enclosure).

Usage Features:

DIP Switch Settings:
- Nominal Current (Dip 1, 2, 3): Configures the motor phase current.
- Current Profile Management (Dip 4, 5):
  - Type A (OFF, OFF): Standard current profile.
  - Type B (OFF, ON): Enhanced motor smoothness, lower acoustic noise and vibrations. Smoothing effect depends on resolution setting.
  - Type C (ON, OFF): Enhanced motor torque.
  - Type D (ON, ON): Mixed (not recommended).
- Resolution (Dip 6, 7, 8): Configures steps per revolution, ranging from 400 to 12800 steps/rev.
Jumpers:
- FC (Automatic current reduction): ON disables, OFF activates (default).
- CO (Current off input): ON forces input to ON, OFF makes input available (default).
LED Status Indicators:
- LED HV (green): ON indicates supply voltage within working range; OFF indicates no supply voltage or out of range.
- LED FAU (red): ON indicates drive is in a non-working state due to thermal protection (if LED TER is ON), max/min voltage, or short circuit/wrong motor connection. OFF indicates drive is active.
- LED TER (yellow): ON indicates thermal protection; OFF indicates drive is active.
Connection Examples: Supports NPN, PNP, 5 Volt TOTEM-POLE (PUSH-PULL), and DIFFERENTIAL (LINE DRIVER or RS422) control system outputs.
Installation:
- Must be installed by a professional assembler.
- For A-NDC 94, A-NDC 96, A-NDC96.S models, the case must be removed (by unscrewing two "A" screws) to set FC and CO jumpers.
- Drives, power supply, transformer, and cables should be located within the same enclosure, hermetic to electromagnetic fields.
- A filter (e.g., CORCOM mod. 6VDK1) should be interposed between the transformer primary and the main, located near the supply entrance.
- Only shielded cable should be used for motor and drive connections (outside the enclosure).
- Connection to Protective Earth terminal (PE) must be short and have low inductance.
- Use a supply transformer with a metal shield between primary and secondary windings, connected to earth.
- Install the drive vertically (not upside down) with at least 5 cm of free space above and below, and 1 cm to the left and right, ensuring air gratings are not obstructed.
- Maximum surrounding air temperature must be below 40 °C.
- Installation is allowed in local environments with pollution degree N° 2. Forbidden in explosive, flammable, chemically aggressive, electrically conductive gas/vapor/dust environments, or near easily flammable/heat-sensitive materials.
- Not for safety-related functions (EN 60204-1) or applications where a driver fault could create hazardous conditions.
- Settings and connector insertion/extraction must be done with the drive switched off.

Maintenance Features:

Forced Cooling: May be necessary depending on operating conditions (ambient temperature, current setting, duty-cycle). To determine if forced cooling is needed, measure the drive heatsink temperature. If it exceeds 65-70°C under the most unfavorable working conditions, forced cooling is required for reasonable drive longevity.
Troubleshooting: The LED FAU (red) and LED TER (yellow) indicators provide diagnostic information regarding the drive's operational status and potential issues like thermal protection, voltage problems, or motor connection faults.
Residual Voltages: Depending on the supply type and application conditions, a waiting time greater than 5 seconds after switching off may be necessary before handling.
Scald Hazard: Components can operate at high temperatures (120°C). Wait several minutes after switching off to avoid scalds.