Observed Pixel-1211-02-0 Connection Failure
SMLogix could not discover a Pixel-1211-02-0 through a Regin USB-to-RS-485 converter, even after multiple port-setting changes. During each connection search, the controller's C1 indicator blinked, but the connection did not complete. Prior success using the same converter with a Corrigo device confirms only that the converter worked in that separate application.
Interpret the C1 Blink as a Turnaround Clue
The reported diagnosis is that the C1 blink indicates the Pixel received a Modbus request and attempted a response. The suspected failure is converter turnaround: the USB-to-RS-485 converter may still be switching from transmit to receive while the controller sends its reply. This is a diagnostic hypothesis based on the indicator behavior, not a measured timing result.
Changing parity or stop-bit values arbitrarily is therefore unlikely to address the suspected timing failure. The evidence also reports that these settings were not exposed in the attempted workflow, although it does not identify the exact SMLogix screen or software version.
Test the Connection at a Lower Communication Speed
- Select a lower supported communication speed for the connection. The evidence does not specify an exact lower value, so do not invent one.
- Ensure the controller-side and computer-side selections refer to the same communication speed.
- Run the SMLogix connection search again and observe both the C1 indicator and the discovery result.
- If discovery succeeds only at the lower speed, treat converter direction-change timing as the leading cause. If C1 still blinks without discovery, the evidence does not establish whether the remaining fault is turnaround timing, wiring, or another communication setting; test a different converter before changing undocumented parameters.
The lower-speed test is relevant because the reported guidance states that lower communication speeds provide slightly longer timeouts. It is the only evidence-supported corrective adjustment for the Pixel-1211-02-0 case.
Do Not Transfer Pixel 25xx Settings Without Validation
A separate configuration note covers Pixel 25xx connections. It does not establish the correct settings for Pixel-1211-02-0, so use it only to identify the settings that must be verified in model-specific documentation.
| Target and interface | Reported settings | Applicability |
|---|---|---|
| Pixel 25xx with device identified as “MOXA 11500” | 115200 baud; 8 data bits; odd parity; 1 or 2 stop bits; no flow control | The device identifier is ambiguous and the settings are not confirmed for Pixel-1211-02-0 |
FAQ
Why does Pixel C1 blink but SMLogix finds no controller?
The reported interpretation is that the Pixel received the Modbus request and responded, but the USB-to-RS-485 converter may not have switched from transmit to receive quickly enough to capture that response.
How do I test a slow USB-to-RS-485 converter with Pixel-1211-02-0?
Select a lower supported communication speed, keep the speed consistent at both ends, and repeat the SMLogix search. Success only at the lower speed supports the converter-turnaround diagnosis.
Should Pixel-1211-02-0 use 115200 baud and odd parity?
The evidence assigns 115200 baud and odd parity only to a separate Pixel 25xx configuration involving a device identified as “MOXA 11500.” It does not confirm those settings for Pixel-1211-02-0.