The YOKOGAWA ACM12, also cataloged as the ACM12 Communication Module, operates as a dedicated hardware component for serial data exchange within industrial control networks. This module provides an RS-422/RS-485 physical interface, facilitating point-to-point or multipoint connectivity for external devices requiring half-duplex communication protocols.
Note: The provided documentation contains conflicting data regarding the ACM12 functionality (referencing both serial communication and 16-channel analog input). This datasheet adheres to the primary serial interface specifications.
| Parameter | Specification |
|---|---|
| Model | ACM12 |
| Brand | YOKOGAWA |
| Origin | Not specified |
| Weight | 0.3 kg |
| Dimensions | Not specified |
| Operating Temp | -20 deg C to 70 deg C |
| Power Consumption | 310 mA (5 V DC), 500 mA (24 V DC) |
| Interface | RS-422/RS-485 (1 port) |
| Speed | 1200 to 19200 bps |
| Transmission Distance | Max 1200 m |
The ACM12 utilizes start-stop synchronization for serial data transmission, supporting both ASCII and binary coding formats. To maintain data integrity over the maximum 1200 m transmission distance, the module implements parity checking (Odd/Even/None) and configurable character/stop bit lengths. When configured for multipoint connectivity, the module functions as a deterministic node in the communication chain, requiring precise termination at both ends of the RS-485 bus to prevent signal reflections.
Q: Why is "No parity" unavailable at a communication speed of 19200 bps?
A: The restriction is due to timing constraints within the module's UART processing logic at higher baud rates. When operating at 19200 bps, the system requires the parity bit to ensure sufficient frame synchronization and error detection.
Q: How can signal reflections be mitigated in a 1200 m multipoint network?
A: Reflections are typically caused by impedance mismatch. Ensure that the bus is terminated at both ends using 120 Ohm resistors and that the cable characteristic impedance is matched to the transceiver requirements.
Our production line was down due to a faulty Bently Nevada monitor. We found it in stock here and they shipped it via DHL immediately. Back in operation within 48 hours—truly a lifesaver for our plant.
Finding brand new, original modules is critical for our safety. This team delivers factory-fresh components with full certification. Their commitment to only selling new products makes them our most trusted partner.
We have sourced Honeywell and Schneider parts here for two years. Every shipment arrives well-packaged with original factory seals intact. Clear communication and the best lead times in the industry.