7-60
Chapter 7. PARAMETER SETUP
(5) Example: Using Azbil Corporation’s PGM ** 2A1 series
V
SSR
: 3 to 6 V
Z
: 260 Ω ± 5 %
V
D
: 0.8 to 1.3 V
• What value should IO be set to when connecting one PGM?
As shown in the figure on the right, a fixed-current system is used
for the voltage output of this controller. The fixed current can be
calculated as follows from the input voltage range of PGM:
8.9 mA ≤ 1 ≤ 17.2 mA
I
MIN
× Z
MIN
+ V
D/MIN
> 3
I
MIN
> 8.9 mA
I
MAX
× Z
MAX
+ V
D/MAX
< 6
I
MAX
< 17.2 mA
• How many PGMs can be connected?
A current of 8.9 mA or more must flow to a single PGM. On the
other hand, the maximum current of the controller is 22.0 mA.
Accordingly, two PGMs can be connected in parallel.
In the case of a series connection, due to the maximum output
current (22.0 mA) and allowable load resistance (600 Ω), the
maximum voltage that can be applied to a load becomes 13.2 V
(22.0 mA × 600 Ω).
When a current of 8.9 mA flows to a PGM, the maximum voltage
at both of its input terminals becomes 3.7 V.
0.0089 × 260 × 1.05 + 1.3 = 3.7 V
Accordingly, 13.2 ÷ 3.7 = 3.56, which means that three PGMs can
be connected in series.
The above calculation assumes operation in the worst conditions.
For example, even if four PGMs are connected in series, they
should operate normally if a voltage of 3 V or more is applied to
each of the PGMs in a voltage ON state.
●
●
C
9
0
(Special functions)
• Normally set to 0.
• In the case of setup 102, current output (including heat-cool out-
put) 0 to 100 % for the control output becomes 0 to 20 mA. Note,
however, that at 0 % or less, the current is 0 mA.
At output 1 mA or less, accuracy is ±0.5 %.
• In the case of setup 103, current output (including heat-cool
output) and auxiliary output 0 to 100 % for the control output
becomes 0 to 20 mA. Note, however, that at 0 % or less, the current
is 0 mA.
At output 1 mA or less, accuracy is ±0.5 %.
• When set to 104, the rate time (d, dd) and reset time (I, dI) settings
are in units of 0.1 s.
• When set to 105, the rate time (d, dd) and reset time (I, dI) settings
are in units of 0.01 s.
Z
I
PGM ** 2A1
DCP31
V
D
