Arroyo Instruments TECSource 5400 Series - Digital Outputs and Relay Control Functions; Digital Output Functions; Relay Operation

5400 Series TECSource User’s Manual · Page 29
Digital Outputs
The 5400 has two digital outputs: Digital Output 1 and Digital Output 2. They
share a common ground with the digital inputs and 5V auxiliary power supply.
Each digital output can be directly set to be Off (0V) or On (5V), or assigned a
function to control its output state. The available functions are:
 Output On – the digital output will turn on when the TEC output is on
 Stable – the digital output will turn on when the instrument is
considered to be stable (see Tol Time and Tol Temp settings)
 T Limit – the digital output will turn on if the temperature limit is
exceeded
 I Limit – the digital output will turn on if the instrument is operating at its
current limit.
 Remote – the digital output will turn on if the instrument is in remote
mode.
 V Limit – the digital output will turn on if the instrument is operating at its
voltage limit.
Each digital output includes a 249Ω series resistor, limiting current draw to
about 20mA. If the output is to be used as a signaling LED, in many cases, an
LED can be directly connected across the digital output and ground.
Each digital output has an invert setting to reverse the state of the output if an
active low signal is required. These settings can be found in the Digital I/O
Menu » Do# Func and Do# Invert menu entries.
Relay
In addition to the digital outputs, the 5400 has an electro-mechanical relay which
can be used as an isolated contact for applications such controlling external
solenoids for valve control, or powering on an external piece of equipment (1A,
30VDC maximum). Relay control is identical to the digital output control, with all
of the same functions available. There is no invert function, but both the normally
open and normally closed contacts are available, allowing for either polarity to
be wired in.
The N/C (Normally Closed) pin 6 will be closed (shorted) to the common pin 19
when the unit is powered off or when the relay is in the “off” state. Similarly, the
N/O (Normally Open) pin 7 will be open (not shorted) to the common pin 19.
When the relay is energized, either by changing the menu setting to On, or when
the assigned function is true, the polarity will reverse: pin 6 will be open (not
shorted) and pin 7 will be closed (shorted) to the common pin 19.