Download Encoder Driver Interface Module

ALLEN-BRADLEY
Encoder Driver Interface Module
Instructions
General
The Encoder Driver Interface Module is a multi–purpose pulse amplifier
primarily used for generating 15 milliampere, double ended, sink and
source output signals. These signals are acceptable as inputs to digital
reference and/or digital feedbacks into opto isolated circuits of
Allen–Bradley drive products such as the Bulletin 1395, 1336 PLUS, 1336
FORCE and the 1399. The opto–isolated input signals are designed to
guard against signal common loops and also to provide an improved signal
to noise input circuit.
Module Capabilities
The Encoder Driver Interface Module has the capability of handling 2
independent quadrature encoder signals, with inputs designated as AI1
(TB1–1) and BI1 (TB1–2) for encoder 1 and AI2 (TB1–3) and BI2
(TB1–4) for encoder 2 (see Fig.1). These inputs are single ended, as they
all are 0 to 5 volt signals referenced to module common (TB1–6 &
TB1–8). Since the module inputs must be a maximum of 5 volt level,
input resistive voltage dividers for example can be applied to reduce 12
volt encoder levels to the 5 volt level. If it is desirable to “Fan Out” one
encoder that has double ended 0 to 15 milliampere levels, it is
recommended that a burden resistor (330 ohms), be mounted near the
module input (within 300 millimeters (1ft.)) for optimum noise immunity
for each channel.
The module outputs are all differential (or double ended), 0 to 5 volt
signals. The module outputs all have the capability of continuously driving
a total load of at least 45 milliamperes. Encoder 1 module outputs are
denoted AO1 (TB2–1), & NAO1 (TB2–2) for the A Channel and BO1
(TB2–3) & NBO1 (TB2–4) for the B channel. In a similar manner,
Encoder 2 module outputs are denoted AO2 (TB2–7) & NA02 (TB2–3) for
the A channel and BO2 (TB2–9) & NBO1 (TB2–10) for the B channel.
The Encoder Driver Module requires a DC power supply capable of 250
milliamperes minimum. The preferred input voltage is 12 volts, but the
internal 5 volt regulator and heat sink in the module will accept up to a 24
volt input power supply. The Encoder Driver Module also has 4 terminals
internally connected together which are dedicated for signal shield
connections. These terminals are TB1–5, TB1–9, TB2–5 and TB2–6.
Specifications
Electrical Input Signal:
Electrical Output Signal:
Single ended; 0 to 5 volts; 0 to 50 Khz
throughput frequency; Input impedance
greater than 100 K ohms.
Differential; 0 to 5 volts; 0 to 50 Khz
throughput frequency; 45 milliamperes
maximum per output.
Instructions
Encoder Driver Module
Electrical Power Supply Input: 12 to 24 volts; 250 milliamperes
minimum current dependent on # of
outputs utilized.
Environmental: Ambient temperature rating: 0 to 40° C (32 to 104°F)
Relative Humidity: 5 to 95% non–condensing
Altitude: 3300 feet (1000m) without derating
Applications
1395 RTP DC Drive – The Encoder Driver Interface Module was
originally developed for Goss, GSD applications using the Bulletin 1395
RTP DC drive (Fig. 1). In this application, both the encoder used for drive
feedback, denoted Belt Speed Encoder, and the magnetic pickup, denoted
Press Speed Pick–up, are routed to a console side panel designed by Goss.
The signals are used for processing roll diameter information and for
setting up roll transferring operations. The signals that are brought out of
this CPTC panel for drive input are single ended, 0 to 5 volts in magnitude,
with severely limited current capability similar to a TTL gate output. The
Encoder Driver Interface Module is designed so that these voltage signals
can be changed to the proper impedance levels for the 1395 RTP digital
reference and digital feedback signals. In order for the module to provide
an improvement in noise immunity, it is recommended that the module be
physically located as close as possible to the voltage source of its input
signals (300 millimeters (1ft.) or less).
Belt Speed Encoder Feedback signals are connected as follows:
1. Encoder Channel A out of the RTP console (CPTC Board) is
connected to the AI1 channel (TB1–2).
2. Encoder Channel B out of the RTP console is connected to the BI1
channel (TB1–1).
3. Module outputs described previously for encoder 1 are directly
connected to the 1395 feedback encoder input terminals.
Figure 1.
1395 RTP DC Drive Application
Paster Panel CPTC Board
Encoder Driver Interface Module
TB2
1
2
3
4
5
6
7
8
9
10
TB1
1
A
B
2
Belt Speed
Encoder
300 PPR
RTRN
6
SHD
HI
Press
Speed
Pickup
RTRN
SHD
12VDC
5
3
TB1
TB1
7 8 9
To Power Supply
2
To Drive
Encoder
Feedback
Input
RTP
Adapter
Press
Speed
Reference
Input
Instructions
Encoder Driver Module
Press Speed Pick–Up signals are connected as follows:
1. Only the channel A input is used, the HI signal is connected to AI2
channel (TB1–6).
2. Module outputs for the encoder 2 channel A output only are
connected directly to the RTP digital ref adapter PC Board
terminals.
Quadrature Encoder/ Multiple Inputs – Figure 2 depicts one quadrature
encoder (with 0 to 12 volt, 15 milliampere outputs) that will be used to
provide digital reference signals for four different drive inputs. Note that
in this application it is necessary to both provide burden resistors for the
outputs of the 12 volt encoder as well as voltage dividers to bring the input
signal level to a maximum of 5 volts.
Figure 2.
Encoder Driver Module Multiple Input Application
Encoder Driver
Interface Module
Single Ended Input
Connections
A
500Ω/ _watt
330Ω/ _watt
CHA
TB2
AO1 1
30 mA
NAO1 2
TB1
1 AI1
3
0 to 12V
6
AI2
30 mA
Common
A
TB2
5
B
7
NAO2 8
AO2
To Drive 1
To Drive 2
To Drive 3
To Drive 4
5
6
Shield
TB2
TB1
2 BI1
500Ω/ _watt
Differential
Output
BO1 3
To Drive 1
NBO1 4
330Ω/ _watt
CHB
4
BI2
9
NBO2 10
BO2
0 to 12V
8
Common
B
TB1
7
9
–
To Drive 2
To Drive 3
To Drive 4
+
Note: Input AI1 Drives AO1, NA01 Outputs
Input BI1 Drives BO1, NB01 Outputs
To 12 – 24 VDC, at 250 milliamps minimum
Power Supply Output
3
Instructions
Encoder Driver Module
Quadrature Encoder/ Impedance Isolation – Figure 3 depicts a single
quadrature encoder used for impedance isolation of the drive feedback
input signal on an AC drive. In this case, the feedback input signal of a
1399 AC drive is isolated from other controllers using the same encoder
signals, which are creating common loops resulting in noise interference
with the feedback signals of the 1399 drive.
Figure 3.
Encoder Driver Module Impedance Isolation, 1399 Drive
Encoder Driver
Interface Module
Encoder A
Encoder B
TB1
1 AI1
CH 1
Input
2 BI1
CH 1
Output
TB1
5
TB Shields
DRIVE
SIDE
BO1 3
NBO1 4
A
A
B
To Switch
Cabinet etc.
B
TB2
5
TB1
3 AI2
CH 2
Input
(Not Used)
4 BI2
Encoder Power
Supply Common
TB2
AO1 1
NAO1 2
CH 2
Output
(Not Used)
6
TB2
AO2 7
NAO2 8
BO2 9
NBO2 10
NOT
USED
Common
TB1
Common
7
8
–
+
12 VDC Power Supply, 250 milliamperes minimum
Tools and Equipment
4
You will need the following equipment to successfully install the Encoder
Driver Module:
• A small flat blade screwdriver
• A wire stripper
• An electric drill
• 2 mounting screws (8–32) and a tap
• Cable, Alpha 2256 or equivalent
Instructions
Encoder Driver Module
Mounting
!
!
ATTENTION: The ED Module and Allen–Bradley AC & DC Drives
all contain ESD (Electrostatic Discharge) sensitive parts and
assemblies. Static control precautions are required when installing,
testing, servicing or repairing this assembly. Component damage may
result if ESD control procedures are not followed. If you are not
familiar with static control procedures, reference A-B publication
8000-4.5.2, Guarding Against Electrostatic Damage or any other
applicable ESD protection handbook.
ATTENTION: Severe injury or death can result from electrical shock,
burn, or unintended actuation of controlled equipment. Hazardous
voltages may exist in the cabinet even with the circuit breaker in the off
position. Multiple sources of power may be connected to the Drive.
Recommended practice is to disconnect and lock out control equipment
from all power sources and discharge stored energy in capacitors, if
present. If it is necessary to work in the vicinity of energized
equipment, the safety related work practices of NFPA 70E, Electrical
Safety Requirements for Employee Workplaces, must be followed. DO
NOT work alone on energized equipment!
1. Remove all power to the Drive.
2. The Encoder Driver Module is supplied with a mounting bracket for
mounting in an appropriate enclosure outside the drive cabinet. It
should be located as close to the reference device (encoder etc.) as
possible. The module can be mounted in any orientation, but it must
be isolated from vibration, temperatures outside the range of 0° to
+40°C (32° to 104° F) and any contact with liquids, chemicals or
volatile gas/dust.
Connections
1. Terminal strip TB1 on the Encoder Driver Module is used for
incoming reference signal and power supply terminations as shown in
Figures 1 thru 3. Incoming signals from a reference
device could be connected are shown in these examples.
2. You must provide power in the range of 12VDC to 24VDC to the
Encoder Driver Board at TB1 Terminals 7 & 8. In 1395
applications, 12VDC can be obtained from terminals 13 & 14 of TB3
provided the total load is not greater than the capibility of the 12 volt
supply. If 24VDC input power is desired it must be provided from a
separate 24V power supply. The Encoder Driver Board has an internal
regulator that automatically compensates, allowing it to operate with
either power source. The module mounted heat sink will dissipate more
power with the 24 volt supply input.
3. The Encoder Driver Board output signals originate at TB2. Use the
examples in Figures 1 thru 3 as a reference when making output
connections.
5
Instructions
Encoder Driver Module
4. After all terminations have been made for your particular application,
reapply Power to the Drive and check the Encoder Driver Interface
Module for correct operation.
Troubleshooting
If the Encoder Driver Module does not seem to be operating properly
check the following:
1. Check that all connections and cables are undamaged and are securely
and correctly connected at the ED Module, the Digital Reference
Adapter Board and the reference device.
2. Check that the ED Module has correctly rated DC power applied to it.
!
ATTENTION: Potentially fatal voltages may result from improper
useage of an oscilliscope or other test equipment. The oscilliscope
chassis may be at a potentially fatal voltage if not properly grounded.
If an oscilliscope is used to measure high voltage waveforms, use only
a dual channel oscilliscope in the differential mode with X 100 probes.
It is recommended that the oscilliscope be used in the A minus B
Quasi–differential mode with the oscilliscope chassis correctly
grounded to an earth ground. Refer to equipment safety instructions for
all test equipment before using with the Encoder Driver Module or
1395 Drive.
3. Check the encoder for proper power supply connections & value of
supply.
4. Check the encoder outputs as well as any interface electronics between
the encoder and the output terminals to the module.
5. If encoder outputs and signal outputs are correct, check signal channel
outputs for pulse train information with the encoder rotating.
6. For Quadrature encoder signals, use a dual trace oscilliscope with A
minus B differential capability to look for the correct differential pulse
train coming into the drive at the Digital Reference Adapter Board. If
the correct pulse train is not present, the ED Module may be
malfunctioning.
7. DO NOT attempt to open or repair a suspect Encoder Driver Module.
Return the unit to an authorized Allen–Bradley service center for repair
or replacement.
6
Instructions
Encoder Driver Module
Figure 5.
Schematic Diagram Encoder Driver Interface Module
D2
D4
+5V
D1
TB1
Encoder #1
Input
AI1
1
R1
2
AI2
3
4
R2
6
7
1A
9
8
R4
18
1Z
2A
15
15
3A
4A
+5V
49.9
C7
0.01
2Y
U1
75174
2Z
3Y
3Z
4
C9
0.01
4Y
12
C6
0.01
TB2
1Y
49.9
17
49.9
BI2
1
3
16
R3
Encoder #2
Input
D3
15
49.9
BI1
16
VCC
4Z
8
C8
0.01
2
3
6
13
2
NAO1
3
BO1
4
NBO1
7
AO2
8
NAO2
9
B02
7
9
11
11
14
AO1
5
5
10
1
4
12
Encoder #1
Differential
Outputs
13
14
10
Encoder #2
Differential
Outputs
NBO2
TB1
8
HS
+12V
Common
+5V
In
2
U2
Out
+12V
1
6
7
MC7805
+12V PWR Input
TB1
+
5
C1
10
C2
0.1
C3
0.1
C4
0.1
C5
0.1
9
TB2
Common
Shield
5
0
6
+5V
TB1
10
+5V Output
NOTE: Unless otherwise specified:
1. All capacitors are in MFD
2. All Diodes are in 4148
3. Last Used: U2 R4
C9 D4
TB2
4. All Resistor Values are in Ohms
5. Maximum throughput frequency 50 Khz
7