Delta RMC101 - Manual (Page 253)

Digital I/O 5.1
Communications 5-3
Figure #2: SSR switching resistive load; low-side configuration
To calculate the maximum current through the SSR in the above diagram, we assume zero SSR
resistance:
Max. current = 24V / 470W = 51.1mA
Max. current = 5V / 470W = 10.6mA
Notice that both maximum current are well within the ratings. To calculate the typical current
through the SSR, we use the typical SSR resistance of 25W:
Typical current = 24V / (470W + 25W) = 48.5mA
Typical current = 5V / (470W + 25W) = 10.1mA
Digital Inputs
The Digital Inputs are compatible with signal levels ranging from 5V to 24V. The Digital inputs
draw 6mA maximum with a 5V input and 10mA with a 24V input.
5.1.2.3 CPU Inputs
Each of the CPU’s two inputs have both a + and - connection. This allows the input to be connected
as either a sinking or sourcing input, which means that most P/C outputs can be connected directly to
the CPU inputs. See the wiring diagrams below.
5.1.2.4 DI/O Inputs
The DI/O inputs consist of a single common and eighteen individual input connections.
Note: The numbered inputs must be positive relative to the ”r;Input Cmn” pin common. That is, these
are sinking inputs.
Most P/C outputs can be connected to the DI/O inputs directly. The exception is open collector