SATEC SA300 ezPAC Operation Manual - Manual (Page 17)

Chapter 2 Device Description Device Outputs
SA300 Substation Automation Unit 17
The VDC input is constantly monitored by the device and can cause the dedicated
indicator LED on the front of the device to light up if the measured voltage drops
below the user defined threshold. See
Advanced Device Setup in Chapter 7 for
information on specifying the nominal (reference) DC voltage in your device.
The VDC drop can also trigger a setpoint to provide an external alarm indication
through a relay output or communications.
Digital Inputs
The SA300 can monitor up to 3 removable 16-channel digital input modules with a
total of 48 inputs. The modules may be ordered with input options for dry contacts, or
10-30V, 20-60V and 30-100V wet inputs.
All digital inputs are sampled at a rate of 16 samples per cycle and synchronized to
the AC sampling circuitry. This gives time stamping of the input transitions with a
1-ms resolution at 60 Hz, or 1.25-ms at 50 Hz.
Digital inputs have a programmable debounce time from one to 100 milliseconds in
groups of eight inputs. Each input can be independently linked to any device counter,
Energy/TOU system register, setpoint, Fault recorder, and Sequence-of-Events
recorder.
The device waveform recorder provides synchronous recording of the 48 digital input
channels together with the AC waveforms making it easy to correlate the operation of
the station protection relays at the time of a fault.
Analog Inputs
The SA300 monitors up to 16 analog input (AI) channels, which may be used for
measuring DC and low frequency currents and volts.
The following plug-in AI modules may be ordered with the device:
4-channel optically isolated 4 AI/4 AO modules with optional ranges of
0-1 mA, ±1 mA, 0-20 mA, or 4-20 mA. The 0-1 mA and ±1 mA analog
inputs can measure 100% overload currents up to 2 mA and ±2 mA.
8-channel optically isolated 8 AI modules with optional ranges of 0-50
mA or ±10 V. They can be ordered with either a regular, or fast AI
sampling option.
The SA300 may be equipped with four 4-channel AI/AO modules, or two 4-channel
AI/AO + one 8-channel AI module, or two 8-channel AI modules.
The scan time for regular analog inputs is 2 cycles (32 ms at @ 60Hz and 40 ms @
50Hz). 8-channel modules ordered with the fast AI sampling option are scanned at a
rate of 32 samples/cycle for waveform recording, and AI readings and triggers are
updated each 1/2-cycle.
Each analog input can be independently scaled to provide true readings in the user-
defined engineering units (see
Programming Analog Inputs in Chapter 7).
NOTES:
1. If you use both 4-channel and 8-channel AI modules in the same device,
put the 4-channel AI modules in slots with lower numbers, i.e., into the left
side slots.
2. If you use regular 4-channel modules and fast 8-channel AI modules, the
regular inputs are scanned at a usual rate.
Device Outputs
Analog Outputs
The SA300 supports up to four removable 4-channel 4AI/4AO modules with a total of
16 analog output channels that can output DC currents proportional to the measured
analog quantities. All outputs are optically isolated and have an internal power
supply. The AI modules may be ordered with 0-1mA, ±1mA, 0-20mA, or 4-20mA