Frequently Asked Questions for
DIN Relays V4
Download a printable manual
Check the spec sheet.
Legacy versions V1 V2 V3
$169 or less. Order now - call
What's new in the product?
What is a relay? How can I wire it
How can I control
How can I power the
DIN relay itself?
What's the new Rest
How do I set up
network access from Windows? ... from a Mac? - Thanks to John McClintock
How can I access the
switch from my own application or remote script? What's the cURL
How do I set up a router to port forward
for Internet access? -Thanks to Mike G. Find
more specific port forwarding
are the contact
What is the
power dissipation? What are the
What size terminals should I use?
Which wire gauge should I use?
I'd like to build a DC / solar powered IP Cam, WiFi AP, or similar DC
powered system. What components do I
What's the Lua
scripting language all about?
How can I keep an
How can I momentarily pulse a relay?
How do I use Wake on Lan?
What are the
mounting hole dimensions?
Do you have a
ruggedized version? Something suitable for mobile use?
What is the default
What wire should I use? How should
I torque the terminals?
How do I reset
What is the default password?
On initial setup, I can't establish a Ethernet communications from a
Windows PC. Help!
Do I need a
How can I send HTTP
Can you develop custom
firmware or hardware for my app?
Can I invert AutoPing or the web page
use the NC contacts?
Do you support PowerMan?
Can you explain the AutoPing
What are the
While we recommend upgrading to the
do have simpler HTTP based Visual Basic.NET,
Python, C++ and
.NET programming examples. There are also
compiled Windows command line Perl examples.
What's new in this product?
In our second version, DIN Relay II, with serial numbers DIN22000 and
higher, we added these features:
- Relay anti-chatter
protection. Maximum relay switching frequency is limited to ~2Hz
for safety and longevity.
- Variable coil current
control. Relay holding and pull-in currents are regulated for
improved efficiency. Power consumption has been reduced by more
than 40% from earlier models.
- Watchdog supervisor.
We've added a second processor which continuously monitors the
microcontroller and reboots it gracefully if necessary.
- Increased memory.
Non-volatile memory has been increased from 16kb to 256kb. No
board is required for
Find the DIN II
In version 3.0 of DIN Relay III, we added these features:
- DC input voltage rating now increased to 48VDC
- Added audio alarm-beeper
- Added 2x16 LCD display to display status and help with setup.
- Added internal real-time-clock with NTP and local time
- Numerous firmware upgrades including scheduling
feature , increased AutoPing speed limit and added more scripting
- Increased relay contact rating and durability
- Added keypad for local control
- Updated rating, testing, and specifications for higher DC input
- Eliminated the internal RJ-45 bulkhead for more reliable connection
to unshielded RJ-45 plastic plugs. Connection status displayed on LCD.
- Case color has changed, manual and box are updated, power consumption has increased slightly
In version 3.1, we added these features:
- Added RS-232 web console for remote machine control. The +5 supply
has been removed. RS-232 has 2.5kv isolation and is brought out to
three screw terminals in the upper right hand corner.
- Added internal UVLO (Under-Voltage LockOut) for more reliable operation on
battery power. UVLO starts at 11.5V and shuts off at 10V to
prevent battery damage. This feature is designed to augment an
existing UVLO/OVP charge controller in battery powered applications.
It is not a substitute for a solar/wind charge controller and doesn't
guarantee proper reset of attached devices in the event that a battery
is highly discharged.
- Minor internal improvements.
Find the legacy DIN
III manual here.
Version 4 (currently shipping) was a complete redesign adding these features:
- Faster processor with 2.4GHz WiFi, SMA antenna. WiFi or hardwired
Ethernet, can be selectable by admin.
- Over-current protection fuses on all relay common lines for safety
- Changed to 3 pin pluggable screw terminals for easier wiring
- Changed input operating voltage range to 12-28VDC. Contact
email@example.com if you prefer 48V or PoE.
- Added more rugged SCR Crowbar over-voltage protection (OVP) with
thermal self-resetting fuse. Kept the 11.5V
under-voltage lockout (UVLO)
- Removed RS232 in lieu of RJ-11 style TTL I/O jack suitable for
connecting DS, DHT or SHT series temperature / humidity sensors.
- Added dual ADC inputs 10-bit, 0-10V default.
- Upgraded thermoplastic enclosure. New external dimensions
2.320 X 4.350 X 6.088 "
- Vast memory expanbsion permits additional software features including: RestAPI, SNMP,
Notifications, SSH, SSL, HTTPS
Find the current DIN4 manual here.
Tell us what you'd like to see in the next version -
What are the contact ratings?
All eight internal T-90 Relays have the following ratings:
Relay Contact Ratings
Relays are rated at 250,000 operations MTBF at 50% load. 800,000 operations
at 10% load. Case terminals are
rated at 12-15A, depending on agency. Only stranded wire
of appropriate gauge should be used.
Here are some wiring suggestions. Use stranded wires only. Note that the common lines
on all relays are internally fused at 12A. Lost or damaged terminal?
No problem. Contact firstname.lastname@example.org
What are the power requirements?
Answer: The relay dissipates an
absolute maximum of 5W during switching with all relays on. Power dissipation decreases with input
voltage due to the use of an efficient switching power supply. Typical
dissipation with relays off is 2W. Although the case is well ventilated,
ambient air temperature should not exceed 140ºF for maximum reliability.
Surges over 32V may trip the SCR crowbar. Power must be disconnected
The relay will shut down at input voltages
below 11VDC. If you expect to encounter brown-out conditions in your
application, set the Power-on-Recovery Mode on the setup page for safest
Please read the UVLO and OVP suggestions below.
Add an external MOV, snubber, or other protection device across the power input
terminals in noisy environments. Read more at dinrelay.com/relaycare.pdf
DIN4 Quiescent Power Requirements
(30mW/relay) when all eight
control relays are ON.
power input is protected by an auto-resetting polyfuse PPTC.
Over-voltage will thermally shut down the polyfuse. Remove the load and allow
60 seconds for the fuse to cool and reset if this occurs.
Can I invert AutoPing or the Web Page to use NC contacts?
Answer: For safety reasons and to prevent support issues, we have not implemented an
"invert relay" function in either the web UI or AutoPing. You can
drive the relays in reverse by:
Setting up a
script to turn a relay -on- in the event of an AutoPing failure.
For example Line 2: "ON 1"
- Use the
AutoPing event to
trigger the script (enter the line number ie 2 of the script for that
You can also use the
programmable web links to start a script. For example, a link like
"CIRCUIT 1 OFF", could be lined to a script 2. ON 1, 3. END. This
inverts the "OFF" operation by closing the relay.
How can I mount to a panel?
Mounting holes are located on 5.8x3.9" square centers with clearance
for #6 screws.
What components do I need to build a
remotely powered DC site using the DIN relay as a power controller?
Answer: In addition to the load (ie. APCam, PtP
link, AP, etc), you'll need a battery, some source of power, ie wind or
solar, and most importantly a charge controller with
UVLO features. Over
Voltage Protection is needed for reasonable battery life. Under
Voltage Lockout is needed to correctly reset attached devices as well as
the DIN relay and to prevent oscillation when the battery is nearly
What is the default IP address? How do I reset to defaults? What is the default
Answer: If you
have lost the IP address or admin password,
follow this procedure to reset to the default IP address of 192.168.0.100:
- Using a small stylus, press and hold the reset button for 5
seconds to enter the reset menu. Select the network reset
The default master login is "admin"
and default password is "1234". This procedure resets the admin login and IP
address and lockout, but doesn't affect outlet names and links.
Wiring and terminal information?
Use stranded wire from 28AWG to 12AWG. Check this wiring table for
Question: On initial setup, I can't establish a Ethernet communications
from a Windows PC. Help!
the instructions in this
How can I control the switch from my
recommend method is using the Rest API -
www.digital-loggers.com/restapi.html If you prefer custom Download
the latest User Utility which includes PowerMan support for
Linux. Your application can use HTTP communications. Note that
using HTTP is generally less secure than the RestAPI.
Here are some HTTP examples
Windows users can download
a Perl interpreter to run scripts.
develop custom firmware for my application?
Gladly. We've done this for many
customers. This is most practical for orders of 500+ units. Generally
there is an NRE, but in some cases labor can be amortized.; After agreeing
on a -very specific- project description,
we can send you an estimate of the time involved to code, debug and test.
Question: Can you develop custom hardware
for my application?
Gladly. We've done this for many customers. Please call with your requirements.
you support PowerMan?
Yes, absolutely. The latest code is here: Download
the latest User Utility here.
How can I momentarily trigger (pulse) a relay?
Just wire a capacitor in series with the
circuit (assuming a DC load). Simple.
Press the existing cycle button in
combination using the NC contact (instead of NO):
Name your circuit here:
A third alternative is triggering a Lua script remotely.
What is a relay? How can I wire it up?
The DIN relay has dry contact FORM-C outputs. They provide whatever
output voltage you connect to them. For example, if you connect a wire
from the positive side of your 24V supply to the COM terminal, then the
NO terminal will provide 24 volts when the relay is switched on, and the
NC terminal will provide 24V when the relay is off. You can operate the
DIN relay on a different voltage than the relay contacts. For example,
the DIN relay could run on 12VDC, but switch 220VAC. You can also use
the relay to switch data, phone lines, or other electrical signals. In
a relay, contacts are electrically isolated from the coil. The DIN
relay controls the coil in the diagram below:
N.O. means Normally Open
N.C. means Normally Closed
COM means COMmon
Each relay is fully isolated, there is no
internal connection between the relays.
A relay schematic looks like this:
Find relay basics here:
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If we haven't answered your questions here, please call (408) 330-5599 or send
us an email. We'll be glad to help.
© Digital Loggers, Inc. 2005.