Yokogawa EJA310A User Manual download pdf

EJA / EJX

FieldGuide

Analog Output Signal

Standard and Namur NE43

FGP-502

1st Edition 01/2009

Yokogawa Corporation of America

2 Dart Road; Newnan, Georgia U.S.A. 30265

Yokogawa EJA and EJX series Brain and HART Protocol

transmitters have an Analog Output Signal (4 to 20 mA)

corresponding to the Primary Variable. The Analog Output

Signal is generated from the digital signal supplied by the

harp

sensor by a 15 Bit D/A signal converter. This conversion

has a resolution of 0.004%. The transmitters are designed to

drive output signals slightly greater than the 4 to 20mA “Base”

signal. The intention is to set analog alarm thresholds

recognizably beyond the normal operating 4 to 20 mA range,

to indicate measurement out of range, and to set further alarm

thresholds to indicate a fault condition.

Measurement Out-of-Range

Standard Analog Output Signal

Yokogawa EJA and EJX transmitters

Standard Analog Output EJA (with option /F1) and EJX

transmitters are factory set to have an Analog Output – Lower Limit

(AO-LL) and Analog Output – Upper Limit (AO-UL) of 3.6mA and

21.6mA respectively [EJA transmitters without Option /F1 output

limits are 3.2mA to 21.6mA]. This allows for a small amount of

linear over-range process readings. This linear over-range signal is

refer to Signal Saturation. During operation, once the AO-LL or

AO-UL limits are reached, the current signal locks to the respective

limit and the transmitter communicates a Measurement Out-Of-

Range event to the control unit via the locked analog signal and

digital communication (Brain or HART); and the indicator (if

equipped) displays an error code. Once the normal pressure is

regained, the transmitter clears the error codes, unlocks the analog

signal and begins to operate as normal.

Example: An EJA110A or EJX110A transmitter is ranged for

0 to 100 inH

O (4 to 20mA).

The Signal Saturation can be controlled by setting the respective

AO-LL and AO-UL. The AO-LL and AO-UL are programmable

within the parameter limits of the transmitter via the digital

communication protocol. Set the limits by entering the value to the

parameter noted below.

Ensure that the control unit receiving the analog signal is setup to

recognize the settings used.

Namur NE43 Analog Output Signal

Yokogawa EJA and EJX transmitters

NAMUR NE43 is a standard used to define the operating AO-LL

and AO-UL values of the analog output signal. Similar to the

Standard analog output signal, Namur NE43 transmitters are

designed to output signals greater than the 4 to 20mA “Base”

signal; allowing for a small amount of linear over-range process

readings (Signal Saturation). Namur NE43 transmitters set the AO-

LL and AO-UL to 3.8mA (-1.25%) and 20.5mA (103.1%)

respectively. Namur NE43 thresholds are set and can not be

programmed to different values through the Digital protocol.

Ensure that the control unit receiving the analog signal is setup to

recognize the Namur NE43 settings used.

1 2 3 4

Summary of Contents

Page 1 - FieldGuide

Page 2 - Up-Scale Burnout

Page 3 - Overview

Page 4 - 1st Edition 01/2009

Yokogawa EJA310A User Manual

Browse online or download User Manual for Sensors Yokogawa EJA310A. Yokogawa EJA310A User Manual [ru]

Summary of Contents

Related models: EJA530A | EJA440A | EJA430A | EJA130A |

More documents for Sensors Yokogawa EJA310A

Comments to this Manuals

Yokogawa EJA310A User Manual

Browse online or download User Manual for Sensors Yokogawa EJA310A. Yokogawa EJA310A User Manual [ru]

Summary of Contents

Related models: EJA530A | EJA440A | EJA430A | EJA130A |

More documents for Sensors Yokogawa EJA310A

Comments to this Manuals

Related products and manuals for Sensors Yokogawa EJA310A