
Automatic Clock Adjustment Switch | Section |
5-3 Automatic Clock Adjustment Switch
Automatic Clock Adjustment Switch (Bit 04 of n)
The Automatic Clock Adjustment Switch is allocated in the CIO Area as shown below. The first word n of the CIO Area is calculated using the follow- ing equation.
n = CIO 1500 + (25 ⋅ unit number)
The Unit control bit is shown in the following diagram.
15 | 14 | 13 | 12 | 11 | 10 | 09 | 08 | 07 | 06 | 05 | 04 | 03 | 02 | 01 | 00 |
n
Automatic Clock
Adjustment Switch
When the Automatic Clock Adjustment Switch turns from OFF to ON, the Ethernet Unit obtains the clock data from the SNTP server on the network, and applies it to the local CPU Unit. After applying the data, the switch auto- matically turns OFF again.
5-4 Automatic Clock Adjustment Error Processing
5-4-1 Automatic Clock Adjustment (SNTP) Errors
The following table shows the main causes and remedies for errors that occur in the automatic clock adjustment function (SNTP).
Cause | Correction |
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SNTP, DNS server address not set | Reset each server address (IP address or |
| host name). |
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SNTP, DNS server communications time- | Inspect the communications path (Ether- |
out | net Unit, cable connections, hub, router, |
| server), and correct the situation that is |
| causing the error. |
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CPU Unit internal clock could not be set | The automatic clock adjustment function |
| is not supported by certain CPU Units |
| (models, lot numbers) if they are in RUN |
| or MONITOR mode. |
RUN | ERC | ERH | LNK | HOST | Probable cause | Correction |
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ON | ON | Flash- | The server (DNS, | Read the error status | ||
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| ing | SNTP) settings in | and error log, and |
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| the Unit Setup are | reset the data in |
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| incorrect. | which the error |
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| occurred. If the error |
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| occurs again, |
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| replace the CPU |
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| Unit. |
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| OFF | Flash- | A Network failure | Inspect the commu- | |
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| ing | has occurred in the | nications path |
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| communications | (Ethernet Unit, cable |
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| path, causing an | connections, hub, |
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| access timeout. | router, server), and |
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| correct the situation |
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| that is causing the |
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| error. |
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