[
X
Troubleshooting ]
- 189 -
HWE10190
GB
[3] Investigation of Transmission Wave Shape/Noise
1. M-NET
transmission
Control is performed by exchanging signals between the outdoor unit and the indoor unit (ME remote controller) through M-
NET transmission. Noise interference on the transmission line will interrupt the normal transmission, leading to erroneous op-
eration.
(1) Symptoms caused by noise interference on the transmission line
(2) Wave shape check
Wave shape check
Check the wave pattern of the transmission line with an oscilloscope. The following conditions must be met.
1) Small wave pattern (noise) must not exist on the transmission signal. (Minute noise (approximately 1V) can be generated by
DC-DC converter or the inverter operation; however, such noise is not a problem when the shield of the transmission line is
grounded.)
2) The sectional voltage level of transmission signal should be as follows.
Cause
Erroneous operation
Error code
Error code definition
Noise interference on
the transmission line
Signal is transformed and will be misjudged as the
signal of another address.
6600
Address overlap
Transmission wave pattern is transformed due to
the noise creating a new signal
6602
Transmission pro-
cessor hardware er-
ror
Transmission wave pattern is transformed due to
the noise, and will not be received normally leading
to no acknowledgement (ACK).
6607
No ACK error
Transmission cannot be performed due to the fine
noise.
6603
Transmission line
bus busy error
Transmission is successful; however, the acknowl-
edgement (ACK) or the response cannot be re-
ceived normally due to the noise.
6607
6608
No ACK error
No response error
Logic
Voltage level of the transmission line
0
V
HL
= 2.5V or higher
1
V
BN
= 1.3V or below
[With transmission]
[Without transmission]
No fine noise allowed
No fine noise
allowed
52
52
52
52
52
V
BN
V
HL
Logic "0"
Logic "1"
0000002115.book 189 ページ 2011年6月4日 土曜日 午前10時48分
Summary of Contents for PUHY-P250YJM-A
Page 1: ......
Page 11: ... 2 HWE10190 GB ...
Page 25: ... 16 HWE10190 GB ...
Page 45: ... II Restrictions 36 HWE10190 GB ...
Page 47: ... 38 HWE10190 GB ...
Page 57: ... 48 HWE10190 GB ...
Page 69: ... IV Indoor Unit Components 60 HWE10190 GB ...
Page 71: ... 62 HWE10190 GB ...
Page 73: ... V Remote Controller 64 HWE10190 GB ...
Page 75: ... 66 HWE10190 GB ...
Page 83: ... 74 HWE10190 GB ...
Page 91: ... VII Refrigerant Circuit 82 HWE10190 GB ...
Page 93: ... 84 HWE10190 GB ...
Page 115: ... VIII Control 106 HWE10190 GB ...
Page 117: ... 108 HWE10190 GB ...
Page 137: ... 128 HWE10190 GB ...
Page 225: ... X Troubleshooting 216 HWE10190 GB ...
Page 227: ... 218 HWE10190 GB ...
Page 272: ......