Yokogawa ADMAG AXF User Manual

Page 40

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IM 01E20D01-01E

4-6

4. WIRING

Connect the AXF integral flowmeter terminal to
external instruments, giving attention to the following
points.

For F

OUNDATION

Fieldbus protocol, please refer to IM

01E20F02-01E.

For PROFIBUS PA protocol, please refer to IM
01E20F12-01E.

4 to 20 mA DC Current Output

Resistive load max. 750

Ω.

(When using BRAIN/ HART communication,
more than 250

Ω, less than 600 Ω).

Receiver

Instrument

AXF integral flowmeter

l+

l-

F0411.EPS

Figure 4.1.10 4 to 20 mA DC Output Connection

Pulse Output

IMPORTANT

• As this is a transistor contact (insulated type),

give attention to proper voltage and polarity
when wiring.

• Do not apply a voltage larger than 30V DC or a

current larger than 0.2A in order to prevent
damage to the instrument.

• When input filter constant of the electronic

counter is large in relation to the pulse width,
the signal will decrease and the count will not
be accurate.

• If the input impedance of the electronic counter

is large, an induction noise from the power
supply may result in inaccurate counts. Use a
shield cable or sufficiently reduce the input
impedance of the electronic counter within the
electromagnetic flowmeter pulse output specifi-
cation range.

• The active pulse output (Optional code EM)

cannot be used in conjunction with the standard
pulse output.

• When the active pulse output (Optional code

EM) is selected, do not be short-circuit between
the DO+ and DO– terminals to avoid damaging
the instrument.

• When the active pulse output (Optional code

EM) is selected, the range of pulse rate must
be set to 2 pps maximum.

• To avoid communication (BRAIN/ HART)

failure, it is recommended to use the shield
cable.

NOTE

For pulse output from the DO terminals, param-
eters must be set. Refer to “Parameter Descrip-
tion” in the user’s manual of the AXF Integral
Flowmeter [Software Edition] (IM 01E20C02-
01E).

F0412.EPS

Mechanical Counter

Electronic Counter

Load

Protective diode

30V DC, 0.2A. max

PULSE OUT

PULSE OUT

AXF integral flowmeter

AXF integral flowmeter

DO+

DO-

DO+

DO-

Figure 4.1.11 Pulse Output Connection

F0413.EPS

Protective diode

PULSE OUT

PULSE OUT

AXF integral flowmeter

AXF integral flowmeter

DO+

DO-

DO+

DO-

Output voltage: 24 V DC

Ϯ20%

• Current: 150 mA or less
Pulse rate: 0.0001 to 2 pps
Pulse width: 20, 33, 50, 100 ms

Mechanical Counter

Electronic Counter

Load

Figure 4.1.12 Active Pulse Output Connection

(Optional code EM)

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