YOKOGAWA ADMAG AXR User Manual page 37

Table 4.6.3 Simultaneous Current-Pulse Output (General - purpose Use/Explosion Proof Type except TIIS)
Connection
Simultaneous Current- When simultaneous output of current and pulse output are used, no communication is possible
Pulse Output in some cases. Read the following example 1 to 3.
Example 1
In this case,
Communication is
possible (up to a
distance of 2 km when
a CEV cable is used)
and when a two-wire
shielded cable is used.
Example 2
In this case,
Communication is
possible (up to a
distance of 2 km when
a CEV cable is used)
and when a one-wire
shielded cable is used.
Example 3
In this case,
No communication is
possible when a three-
wire cable is used.
The range of load The range of load resistance R for the pulse output must basically be 1 kΩ and 2 W. The load
resistance R for the resistance should be selected by calculation as shown below when proper transmission is
pulse output impossible due to the length of cable or frequency of pulse output.
Note: • The communication is possible though it might not meet a part of the HART communication specification depending on use conditions.
• When using current and pulse output simultareously, the HART communication may be influenced by noise comparing analog output
only.
AXR Terminal
Cable
+
Cable
SUPPLY
−
+
DO
−
*8
For the shielded cables in this example,
use two-wire shielded cables
separately for SUPPLY and DO.
No communication is possible
when a shielded cable is not used.
However, simultaneous current-pulse output is possible.
AXR Terminal
Cable
+
Cable
SUPPLY
−
+
DO
−
For the shielded cables in this example,
use two-wire shielded cables
*8
separately for SUPPLY and DO.
AXR Terminal
Cable
+
SUPPLY Cable
−
+
DO
−
*8
E (V)
≤ ≤
R (kΩ)
120 C (μF) × f (kHz)
2
E (V)
.............................. (2)
P (mW) =
R (kΩ)
Description
0.0236 x (R1 + R2+ R3) + 14.7 ≤ E1 [V] ≤ 42
In the case of R3=250[Ω]
0.0236 x (R1 + R2) + 20.6 ≤ E1 [V] ≤ 42
Shielded Cable
Resistance:R1[Ω] *9
+
Resistance:R2[Ω] *9
−
Shielded Cable
*3: This supply voltage requires a power source
with a maximum output current of no less than E3/R.
0.0236 x (R1 + R2+ R3) + 14.7 ≤ E1 [V] ≤ 42
In the case of R3=250[Ω]
0.0236 x (R1 + R2) + 20.6 ≤ E1 [V] ≤ 42
Shielded Cable
Distributor, etc.
Resistance:R1[Ω] *9
+
Resistance:R2[Ω] *9
−
Shielded Cable
*4: This supply voltage requires a power source
with a maximum output current of no less than E3/R.
250Ω
Resistance:R1[Ω] *9
Resistance:R2[Ω] *9
*5: This supply voltage requires a power source
with a maximum output current of no less than (E5/R+0.0236).
E: Supply voltage (V)
0.1
... (1)
f: Frequency of pulse output (kHz)
R: Value of load resistance (kΩ)
C: Cable capacitance (μF)
P: Electrical power of the load resistance (mW)
Note: C 0.1 (μF/km) for CEV cable
<4. WIRING>
Distributor, etc.
R3[Ω]:Load Resistance
R3 E1
*3
*7
R
E3:30 V DC max
+ *6
Electric
−
counter
R3[Ω]:Load Resistance
E1
R3
*4
*7
E3:30 V DC max
R
+
*6
Electric
−
counter
+
Recorder
or other
−
instrument
*5
E5
*7
R
≤
+ +
0.0236×﴾R1 R2﴿ 20.6
+ *6
Electric
−
counter
IM 01E30D01-01EN
4-12
*10
*10
*10
*10
≤
[ ]
E5 V 30