Teledyne T200, Руководство по эксплуатации, Страница: 39 / 425

Teledyne API
– T200 NO/NO
2
/NO
X
Analyzer Operation Manual Getting Started
37
3.3.1.5. CONNECTING THE STATUS OUTPUTS
The status outputs report analyzer conditions via optically isolated NPN transistors that
sink up to 50 mA of DC current. These outputs can be used to interface with devices
that accept logic-level digital inputs, such as Programmable Logic Controllers (PLCs).
Each status bit is an open collector output that can withstand up to 40 VDC. All of the
emitters of these transistors are tied together and available at pin D (see Figure 3-10).
ATTENTION
COULD DAMAGE INSTRUMENT AND VOID WARRANTY
Most PLC’s have internal provisions for limiting the current that the input will
draw from an external device. When connecting to a unit that does not have this
feature, an external dropping resistor must be used to limit the current through
the transistor output to less than 50 mA. At 50 mA, the transistor will drop
approximately 1.2V from its collector to emitter.
The status outputs are through a 12-pin connector on the analyzer‟s rear panel labeled
STATUS (Figure 3-4). Pin-outs for this connector are:
STATUS
1 2 3 4 5 6 7 8 D
+
S
Y
S
T
E
M
O
K
OK
HIG
H RANG
E
CO
NC V
AL
ID
Z
E
RO
CAL
S
P
A
N CAL
DIAG
M
O
D
E
O
2
CAL
+5V to external device
Figure 3-10: Status Output Connector
Table 3-6: Status Output Pin Assignments
OUTPUT # STATUS DEFINITION CONDITION
1
SYSTEM OK
On if no faults are present.
2
CONC VALID
On if O
3
concentration measurement is valid.
If the O
3
concentration measurement is invalid, this bit is OFF.
3
HIGH RANGE
On if unit is in high range of DUAL or AUTO Range Modes.
4
ZERO CAL
On whenever the instrument is in
CALZ
mode.
5
SPAN CAL
On whenever the instrument is in
CALS
mode.
6
DIAG MODE
On whenever the instrument is in DIAGNOSTIC mode.
7-8
SPARE
D Emitter BUS The emitters of the transistors on pins 1 to 8 are bussed together.
SPARE
+ DC Power + 5 VDC, 300 mA source maximum
Digital Ground
The ground level from the analyzer’s internal DC power supplies. This
connection should be used as the ground return when +5VDC power is used.
06858E DCN7057