Eaton MTL5514D - Analogue Input (AI) Modules

INM 5500 Rev 10
62
8.3 Analogue Input (AI) Modules
All of these tests compare the output current with the input current (A1) over the normal range
of operation, and measure the “error current” i.e. the difference - as indicated on A2. Apply these
tests per channel, as appropriate.
Ammeter A2 must be capable of handling either polarity. If it is not an auto-ranging instrument,
set it to a high range before switch on, then adjust sensitivity to obtain the required reading.
8.3.1 Modules: MTL5541, MTL5544 & MTL55544D
Figure 8.5: AI test circuit #1
Output Measurements
Note: Do not connect a voltmeter in circuit to measure V1 until requested in Step 4 below,
because current measurement A2 could be affected.
1. Adjust RV1 to vary the current (A1) through the range 4 to 20mA
2. The measured current imbalance (A2) over this range should not exceed ± 20µA
3. Adjust RV1 for a 20mA reading on A1
4. The voltage V1, across the channel input, should typically be >16.5V.
8.3.2 Modules: MTL5541S(-T), MTL5544S & MTL5561
Figure 8.6: AI test circuit #2 “o/p sinking”
Output Measurements
Note: Do not connect a voltmeter in circuit to measure V1 until requested in Step 4 below,
because current measurement A2 could be affected.
1. Adjust RV1 to vary the current (A1) through the range 4 to 20mA.
2. The measured current imbalance (A2) over this range for the MTL5541S and the MTL5544S
should not exceed ± 20µA. For the MTL5561 the imbalance should not exceed ± 400µA.
3. Adjust RV1 for a 20mA reading on A1
4. The voltage V1, across the channel input, should typically be >16.5V.
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V1
i/p
o/p
RV1
10kΩ lin.
A1
250Ω
24V
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o
I
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A2
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