Original Siemens 430/440 Inverter/Converter I/O Board /Terminal Board 1790L811A A5E00224211 179OL811A A5EOO224211

1790L811A | Siemens MICROMASTER 440 DeviceNet I/O Unit — 8 DI / 8 DO / 24VDC / IP20 / DIN Rail

MICROMASTER 440 — The Full-Featured Variable Speed Drive

The MICROMASTER 440 (MM440) is Siemens' highest-specification MICROMASTER series inverter — covering general-purpose variable speed drive applications including machine tools, pumps, fans, compressors, and conveyor systems. Unlike the MM430 (optimised for fans and pumps), the MM440 includes full vector control, dynamic braking control, and the broadest I/O and communication option set in the MICROMASTER family.

The 1790L811A I/O unit extends the MM440's native I/O capability — adding 8 dedicated digital inputs and 8 dedicated digital outputs accessible over the DeviceNet fieldbus.

Key Specifications

DeviceNet — The I/O Module's Communication Network

The 1790L811A uses DeviceNet as its communication protocol — connecting the digital I/O expansion to the MM440 drive and/or the plant automation network:

DeviceNet overview: DeviceNet is a CAN-based industrial fieldbus protocol standardised under IEC 62026-3. It operates on a single trunk cable (combination power and data) connecting devices in a linear network topology with short drops to each node. DeviceNet has been widely deployed in North American industrial environments for machine control I/O.

I/O data over DeviceNet: The 8 digital input states and 8 digital output command bits are transmitted as DeviceNet explicit messaging or I/O polling messages — the network master (typically a PLC or drive controller) reads the 8 DI states and writes the 8 DO commands at the configured scan rate.

MM440 integration: The MM440 supports DeviceNet communication through its Communication Board DeviceNet (CBD) option. The 1790L811A I/O unit extends the digital I/O available on the DeviceNet network — adding machine-level sensor and actuator points accessible through the same DeviceNet network that carries drive commands.

Application Scenarios

MM440 DeviceNet I/O expansion: A MICROMASTER 440 drive installation requires more digital I/O points than the drive's native terminals provide. The 1790L811A adds 8 DI and 8 DO to the DeviceNet network — connecting additional machine sensors (limit positions, pressure switches, flow sensors) and actuators (solenoid valves, contactors) to the drive system's control network.

Distributed I/O on DeviceNet machine network: A machine tool or process plant with multiple MM440 drives uses DeviceNet as the machine I/O bus. The 1790L811A provides DIN rail mounted distributed digital I/O nodes on the DeviceNet network — reading machine sensors and driving actuators at each station without individual I/O wiring back to a central panel.

FAQ

Q1: Is the 1790L811A the I/O unit for the MM440 drive itself, or an independent DeviceNet I/O node?

The 1790L811A is a DeviceNet I/O node — its 8 DI and 8 DO are accessible from the DeviceNet master (PLC or drive controller) over the network. It is associated with the MM440 system through its MICROMASTER category classification, but functions as an independent DeviceNet slave node with its own node address. Multiple 1790L811A units can coexist on the same DeviceNet network with the MM440 communication module.

Q2: What DeviceNet master equipment is required to use the 1790L811A?

The 1790L811A operates as a DeviceNet slave — it requires a DeviceNet master on the same network to function. The master provides the network scan clock and exchanges I/O data with all connected slave nodes including the 1790L811A. Typical masters include PLC DeviceNet scanner modules or the MM440's Communication Board DeviceNet (CBD) when configured as a DeviceNet master. Set the 1790L811A node address (MAC ID) to a unique address on the network before connection.

Q3: What does IP20 mean for the installation environment of 1790L811A?

IP20 protects against fingers and solid objects larger than 12mm penetrating to live components — it does not protect against water, liquids, or fine dust. The 1790L811A must be installed inside a sealed control cabinet or enclosure with a higher IP rating (typically IP54 or above) to protect it from the industrial environment. It is not suitable for direct exposure to splashing, dust, or humid atmospheres without an appropriate external enclosure.

Q4: How are the node address and I/O parameters configured on 1790L811A?

DeviceNet node configuration including MAC ID (node address, 0–63) and I/O parameters are typically set via the DeviceNet network using EDS (Electronic Data Sheet) file and network configuration software. The EDS file for the 1790L811A defines the I/O data structure that the DeviceNet master uses to exchange the 8 DI and 8 DO data with the module. Some DeviceNet I/O modules also provide hardware switches for MAC ID selection — confirm from the 1790L811A product documentation.

Q5: Can the LED status indicators on 1790L811A be used for diagnostics without a laptop?

Yes. The per-channel LED indicators on 1790L811A show the live on/off state of each digital input and output without requiring any connected software or diagnostic tool. During commissioning, these LEDs allow the technician to verify that each sensor signal is correctly arriving at the input (LED on when sensor activates) and that each output is correctly commanded from the network (LED on when the master writes a 1 to the output). This visual indication significantly speeds troubleshooting of wiring and I/O configuration issues.