Omron CJ1W-CTS21-E Instruction Sheet

Note: If you only want to connect one SSI encoder, the other SSI

channel has to be disabled in DM m+20, see section Configuring the Unit via DM for further details.

PNSPO

Model

CJ1W-CTS21-E

Synchronous Serial Interface (SSI) Unit

INSTRUCTION SHEET

Thank you for purchasing an OMRON product. Read this instruction sheet thoroughly and familiarise yourself with the functions and characteristics of the product before using it. To ensure safe and correct use of this Unit, also read the following Operation Manual (Cat. No. W393-E1): SYSMAC CJ1 Series Programmable Controllers.

Keep this instruction sheet for future reference.

OMRON MANUFACTURING OF THE NETHERLANDS B.V.

1634330-1A

 Unit specifications

Unit type CJ1 Special I/O Unit Applicable PLC models CJ1-series PLCs Storage temperature -20 to +75 °C Ambient temperature 0 to +55 °C Ambient humidity 10 to 90 % (non-condensing) EMC compliance EN 50081-2, EN 61131-2 Current consumption 300 mA (5V via busconnection) Weight 200 g (typical) Number of words allocated

• 20 CIO-words. First word allocated = CIO2,000 + (Nx10)

• 30 DM-words. First word allocated = D20,000 + (Nx100)

 Dimensions

EXT.PS FOR ENCODERS: 5-24 V DC, 0.8 A max.

CTS21

100x

10x

RUN CH1 CH2

ERC ERH

B1 A1

MACH

CJ1W-CTS21-E

SSI DATA+CLK:RS-422 Line Driver, 1.5 MHz max.

2-CHANNEL SSI UNIT

PNSPO

OMRON MANUFACTURING OF THE NETHERL ANDS B.V. MADE IN THE NETHERLANDS

Lot No. 000000N0000 Batch No. 000000000

! DANGER

Do not attempt to take the Unit apart and do not touch any internal parts while the power is being supplied. Doing either of these may result in electrical shock, and serious or fatal injury.

! Caution

Leave the protective label on top of the Unit as long as the Unit is not mounted and wired completely, in order to prevent wire clippings or other materials from getting inside the Unit. When the mounting and wiring has been completed, the label must be removed to allow air circulation and heat radiation.

 LED Indicators

Name Colour State Unit status

RUN green On Normal operation Off Initialisation error ERC red On Unit error (check CIO n+6, n+7) Off Unit has no errors ERH red On CJ1-CPU Unit error Off CJ1-CPU Unit has no errors

 Nomenclature

Unit status indicators

• RUN (green)

• ERC (red)

• ERH (red)

• CH1, CH2 (green)

Machine number rotary switches

Removable Terminal Block

• Connections for SSI-encoders

• Connection for power supply SSI-encoders

Terminal Block latch

• Slide down to remove

Name Colour State Counter channel status

CH1, CH2

green On Channel configured and is

communicating without errors

Off Channel is not configured or a

communication error has occurred

 Machine Number Switch

Name Function

MACHINE No.

Sets the Machine Number (00 – 94).

• Setting Machine Numbers 95-99 will generate an error.

• Make sure each Machine Number is used only once per CJ1-CPU.

• The next higher Machine Number should not be used on any unit, as it would cause a CIO-data overlap

• Be sure to turn off the power to the Unit before setting the Machine Number.

x10

• Slide up to lock

 Quick Start

1. Set all DM-settings to 0. The Unit is now configured as follows: 400kHz clock frequency, 24 bit Gray-coded and a 40µs monoflop time, for both SSI channels.

2. Set Machine Number.

3. Mount and wire the Unit, the two SSI encoders and the encoders power supply.

4. Turn power on.

5. Create I/O Table.

6. Both green CH1 and CH2 indicators should now turn on.

7. The encoder data can now be read from CIO n+10/11 and CIO n+15/16.

 Terminal Block layout

Notes:

• Electrical isolation is provided for each data input line. Electrical isolation is not provided for the outgoing clock lines. The encoder power supply can be connected to the unit’s connector.

Use the following table to make connections directly to the screw terminals block:

• The power supply should match the encoders specifications.

Item Description

Row B

Terminal

no.

Description Row A

SSI DATA CH1 DATA1 - B1

A1 DATA1 +

SSI Clock CH1 CLOCK1 - B2

A2 CLOCK1 +

SSI Power Supply OUT CH1

0V_ENC_PS¹ B3

A3 +_ENC_PS2

N.C. B4

A4 N.C.

SSI DATA CH2 DATA2 - B5

A5 DATA2 +

SSI Clock CH2 CLOCK2 - B6

A6 CLOCK2 +

SSI Power Supply OUT CH2

0V_ENC_PS¹ B7

A7 +_ENC_PS2

N.C. B8

A8 N.C.

Encoder Power Supply Input

0V_ENC_PS¹ B9

A9 +_ENC_PS2

• Use shielded twisted pair, 2×2×0.25mm

(+ optional 2×0.5mm2

for PS).

• The shield must be connected to the SSI encoder and to the frame-ground near the PLC-system.

• The SSI protocol has no mechanism to reject noise. See section Noise Prevention for more information.

• Recommended maximum cable length by selected clock frequency:

100kHz: < 400m 300kHz: < 100m

200kHz: < 200m

400kHz: < 50m.

 Communication Errors

During normal operation, the SSI Unit can detect three kinds of communication errors (see section Error Processing). At the occurrence of a communication error on channel 1(2):

• the corresponding error code is set in CIO n+6, n+7

• the corresponding error code is stored inside the SSI Unit

• the Global Error Indication bit in CIO (n+8, bit 00) is set

• the ERC-LED is turned on

• the corresponding CH1(2)-LED is turned off

This status will remain, even if during the next SSI-communication no error is detected by the SSI Unit. In this case only the “New valid SSI data received” bit in CIO will be set, indicating that for the current SSI data in CIO no communication error was detected.

(1)(2): All these pins are internally connected.

To clear the above error status, the “Clear Error” bit in CIO has to be set. The following table describes the possible statuses of the SSI Unit after proper initialisation:

 SSI Communication

ERC

LED /

Global

error bit

CH LED

New

Valid SSI data received

bit

Status

Off On On

The channel  SSI data in CIO can be used; no error has occurred.

Off On Off

No new channel  SSI data has been received since last cyclic refresh; no error has occurred.

Off Off Off

Channel  is not configured for SSI communication (see DM m+10/20).

On Off On

The channel  SSI data in CIO can be used; a communication error has occurred earlier *.

On Off Off

The channel  SSI data in CIO cannot be used; a communication error has occurred *.

On On On

The channel  SSI data in CIO can be used; a non-communication error has occurred *.

On On Off

No new channel  SSI data has been received since last cyclic refresh; a non-communication error has occurred *.

Item Specification

CLK lines Non-isolated differential line driver,

RS422 compliant

DATA lines Electrically isolated differential line

receiver, RS422 compliant Number of data-bits 9 to 31 (default: 24) Value coding Gray/Binary/Tannenbaum/Raw

(default Gray) Clock frequency 100kHz to 1.5MHz (default 400kHz) Monoflop time 10µs to 99,990µs (default: 40µs) Sample rate Approx. 2500 Samples/sec with 2

encoders connected

(with default settings)

Default: All DM-settings are 0000

 SSI Circuitry

DATA+

DATA-

CLOCK+

CLOCK-

+_ENC_PS

0V_ENC_PS

Shielded Twisted-pair Cable

SSI ENCODER CJ1W-CTS21-E

ENCODER

B9 A9

RS422

* See Error Processing section for countermeasures.

 Noise Prevention

The symptoms of picking up noise are random jumps in the SSI data values read (CIO n+10/11 and n+15/16). For applications that expect a continuous change of SSI data values, the PLC application can e.g. identify noise by detecting an unexpected large change in the SSI data values or data values outside the expected range.

The best way to prevent noise is by proper wiring the unit as described in the SSI Communication section. An alternative could be to use an SSI encoder equipped with parity.

+ 2 hidden pages

Omron CJ1W-CTS21-E Instruction Sheet

Specifications and Main Features

Frequently Asked Questions

User Manual