Industrial M-1AR Modem

Bo-Sherrel's M-1AR Short Haul Modem (Rev B) is an industrial data‑link device engineered for short‑distance serial communications, originally designed for Reliance Electric, and built to endure rugged factory environments. The model is specified as Short Haul Modem Type M-1AR, Rev B, with typical Power input of 115 VAC at 50/60 Hz, and some listings indicate dual‑voltage variants such as 115/230 VAC to accommodate different plant electrical systems. As a dedicated asynchronous modem, it provides the data‑link capabilities needed to connect legacy controllers and remote equipment over a compact distance, without requiring modern digital protocols. In historical and current distributor listings, the M-1AR is described as a Rev B short‑haul modem; its typical use cases include connecting legacy PLCs, sensors, and remote subsystems in industrial automation and process control setups. The Rev B designation signals a later revision of the design, with most listings tying the M-1AR to Bo‑Sherrel's short‑haul family that served Reliance Electric systems, though exact technical documentation varies by source.