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Typical Cable Test Configurations
2.1 Typical Cable Test Configurations
Each of the following test configurations is a transmission line consisting of a
In addition to the different transmission topologies, the EVM can also be configured to run off two or three separate power supplies, as described in the previous section. This would allow the user to induce a ground shift or offset between the two different drivers and receivers. This setup can be used with any transmission line test.
Table 2−1. EVM Configuration Options
Configuration | Jumpers In | Resistors In | Resistors Out | Diagram |
W1, 2, 7, 8, 9, 10 | R4 | R5, 6, 7 | Figure 2−1 | |
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W1, 2, 7, 8, 9, 10 | R4, 7 | R5, 6 | Figure 2−2 | |
transmission |
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W1, 2, 3, 4, 7, 8, 9, 10 | R5, 16 | R2, 4, 6, 7, 13 15 | Figure 2−3 | |
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2.1.1Point-to-Point Simplex Transmission
1)Connect a
2)Verify resistor R4 is installed.
3)Remove resistors R5, R6, and R7. This properly terminates the transmission line at one end.
4)Enable the driver by connecting the jumper on W2 between pin 1 and pin 2, or U1 pin 4 to VCC.
5)Enable the receiver by connecting the jumper on W1 between pin 2 and pin 3, or U1 pin 3 to GND.
Figure 2−1. Point-to-Point Simplex Transmission
VCC
Signal Source
with
Output
Cable
J2
TP2
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Input Signal | W2 |
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4 | 9 |
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5 |
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R7 | P2 | R6 | |
U1 | 100 | 100 | |
R3 |
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10 |
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49.9 |
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| Twisted Pair Cable |
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| R2 |
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50- | Ω | cable or | Cable | J1 |
| 12 | |
| 453 2 |
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| U1 | R4 | ||||
Active Voltage |
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| 100 | |||
Probe into one |
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| 3 | |||
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| TP1 | 11 | ||||
Channel of Scope |
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| VCC | ||||
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Terminated in |
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High Impedance |
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| W1 | ||
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| Output Signal |
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| Active Voltage |
| Jumper | ||
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| Probe |
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P1 | R5 | |
100 | ||
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Test Setup |