I need a combination of functions that isn’t offered in the Ice Bloc products listed on this page (e.g. 2 x diode driver channels and 2 x temperature control channels). Is this possible?
Yes. Talk to us about your specific requirements and we’ll be happy to help you.
Web interface control and connectivity
How do I set up an Ice Bloc on my network?
The exact procedure varies depending on your network. Generally, if you have a router in your lab, simply use the provided Ethernet cable to connect an Ice Bloc to it, and then enter the IP address listed on the side of your Ice Bloc into a web browser on any networked computer. Otherwise, you can connect the device into your University / Institution network through a wall-mounted Ethernet socket, but you may need to contact network support to have the device approved on the network.
Can I control my Ice Bloc using a mobile phone or tablet?
There are no dedicated mobile phone or tablets app, but you can access the interface from a web browser on your device.
I currently have software for device interfacing over serial / GPIB. How can I send commands over Ethernet?
Most popular programming languages and system design packages (MATLAB, LabView, Python etc.) are provided with libraries for Ethernet interfacing. We recommend consulting the online help for your chosen language to identify how to connect and communicate with Ethernet devices. Commands can then be sent over this connection for controlling all Ice Bloc operations, as detailed in the Ice Bloc Command Set. For example scripts, see the Support page.
If my Ice Bloc is accessible from the university network / Internet, how secure it is?
Access to the Ice Bloc web interface is password protected to prevent unauthorised access. Additionally, manual control over Ethernet using custom software can be limited to certain IP addresses, allowing you to restrict access to particular computers.
Which user account do I use when logging in to the web interface?
Ice Blocs add additional protection by offering multiple levels of access to the web interface: user, supervisor and factory. Generally use a User login. Use Supervisor to set / modify operational options and set, for example, safe drive limits for the connected devices. Factory login is used only by M Squared personnel.
Can I control an Ice Bloc wirelessly?
The Ice Bloc must be connected to the network with an Ethernet cable, although any networked PC can then access it, even over a WiFi connection.
Help, my experiment has stopped working correctly! What can I do?
We recommend enabling ‘logging’ in the Ice Bloc, through the tab on the main Control page. This will generate a daily log file of all the internal parameters, which can often be used to diagnose a problem. In the event of a problem related to your Ice Bloc, please use our support page to get in touch. With your permission, we may remotely access the Ice Bloc to expedite the solution.
Can different users control separate channels of the DD-40 or TC-4 driver simultaneously?
All users have full access to all the capabilities of an individual Ice Bloc (except for configuration options). There is currently no way of assigning limited capability to multiple users.
I need a diode driver. Which product is best for me?
This depends on your diode(s) specifications and target application. If you only need to drive a single diode, consider the DD-TC, which includes a single diode drive channel (up to 20V) and an additional temperature controller channel, which you can use for thermal control of the diode (alongside temperature control hardware, such as a Peltier cooler). However, if you need a higher current supply or to drive multiple diodes simultaneously, we recommend our DD-40 product, offering up to 40A on 4 channels simultaneously. Additionally, all Ice Blocs provide the user-friendly web interface and flexible modular architecture.
Diode Driver questions
Can the DD-40 provide the maximum current (40A) to all four channels simultaneously?
The DD-40 has a maximum power output for all four channels and a maximum output per channel. When you configure each channel with the maximum current and compliance voltage limit for the connected diodes, the total power is calculated and may limit what is available on the remaining channels. If the compliance voltage limit is kept close to the diode voltage (+ cable drop) on each channel then more power is available on each channel. For example, for a laser diode with a forward voltage of 2.2V and a cable drop of 0.3V the compliance limit must be set to just over 2.5V. At 40A this is a channel power of 100W, leaving 150W for the other channels.
Can I use a DD-40 to pulse-drive my laser diode? What is the maximum frequency?
The external modulation bandwidth of a DD40 channel is affected by the output current being drawn from the channel and the modulation depth. It is primarily a CW diode driver with modulation inputs. For small signal modulation (keeping the diode above threshold) the modulation bandwidth is useful up to about 20kHz. For deep modulation (going below threshold) the modulation bandwidth is about 1kHz. For complete on/off diode drive the modulation bandwidth is about 200Hz. If you want to pulse drive a diode at high frequency this really needs done very close to the diode or the cable inductance will significantly affect the behaviour of the system. At its most extreme the cable inductance can result in damage to the diode.
Will this work with LEDs as well as laser diodes?
Yes, both laser diodes and light-emitting diodes can be controlled by an Ice Bloc diode driver. The maximum output compliance of the DD40 is 5V which is enough to drive most single LEDs but maybe too low for some high power white / blue LEDs.
Does Ice Bloc include diode protection?
Yes, under a supervisor login the maximum drive current, maximum compliance voltage and current ramp rate can be set, per channel. In addition, should a channel be enabled with no diode connected it will be immediately shut down. However, as for every high current system, extreme care must be taken to ensure that the electrical connections between the diode driver and the diode are reliable and can handle the current. Accidental short circuits across the diode or from either of its terminals to ground can result in damage to the diode. Also ensure that both connections (anode and cathode) of the diode are ‘floating’. Neither diode connection must be connected to the ground, the optical bench or any other accessible metalwork. All our diode drivers are designed and tested such they do not generate output transients under any operating conditions. The DD40 can also be interlocked through the network connection with a TC4 temperature controller. Should the temperature of the diode go out of limit, the diode drive channel will shut down. This process, when enabled, is ‘failsafe’ such that if the DD40 does not receive a response from the related TC4 channel it will shut down.
Can I connect two Ice Bloc diode drivers in parallel to achieve higher drive current for a single diode?
No. The output current of each unit is carefully monitored and stabilised, so combining the outputs in parallel may lead to instability. If you need to drive a high-power diode, consider our DD-40 Ice Bloc offering up to 40A per channel, or contact us for further enquiries.
I have a DD-40 offering 40A per channel and four channels. However, I want to supply 80A on a single channel. Is this possible to combine the output from different channels on the same Ice Bloc?
No. The outputs of a DD40 cannot be paralleled. If you need higher current drive, please contact us.
Temperature Controller questions
Can Ice Bloc TC-4 automatically determine PID (proportional-integral-derivative) control parameters for automatic temperature control?
This is currently in development. The quick start guide gives examples of starting PID values. To help optimise the control loops the TC4 plots the temperature error in real time so the effect of changes can be seen immediately.
What’s the minimum/maximum temperature the TC can measure?
It’s set from -70°C to +200°C. This covers most photonic device applications. Contact us if you need a wider range.
I have a TC-4 offering 10A per channel and four channels.
Can I combine the output from different channels on the same Ice Bloc?No. The outputs of a TC4 cannot be paralleled. If possible use two smaller TECs in series on one channel. If this still cannot provide enough cooling (or heating) and if the operating load conditions are known then a second TEC/heater can be driven at a constant power from another TC4 channel, supplying some of the ‘steady state’ cooling/heating requirement. Contact us for other options.
QCL Driver questions
What is the output current noise level of the Ice Bloc QCL driver?
The standard QCL driver with an output current up to 1A has an output current noise density of less than 2nA/√Hz from 10Hz to 1MHz.
Can the noise level be lower?
Yes. Please contact us to discuss what you need. We design everything we make and can almost certainly optimise the system performance around your requirements.
Can the output current be higher?
Yes. Please contact us to discuss what you need. The Ice Bloc QCL driver was designed around particular customer requirements. Let us know what you need and we’ll let you know if we can do it.
What is the resolution and accuracy of the temperature controller in the QCL driver?
The temperature controller is optimised for use with standard NTC thermistors as they give the highest sensitivity to temperature change. Using a standard thermistor with a T25 of between 10k and 100k the temperature resolution of the controller is under 1mK. The thermistor type and characteristics can be defined through the temperature controller setup user interface. The thermistor voltage is digitised using a high precision 24 bit A/D converter with a 1ppm/°C reference, so it’s very stable against internal and ambient temperature changes. The absolute temperature accuracy is usually determined by the thermistor tolerance. The precision of temperature control of the QCL is affected by several factors, the main one being the thermal / mechanical proximity of the thermistor to the QCL device. With reasonable care 1mK can easily be achieved.
What is the range of the PID control loop settings?
The PID control loop runs in a Digital Signal Processor using floating point arithmetic so the range of PID values is practically unlimited. The same algorithm in our TC4 temperature controller can handle thermal time constants from fractions of a second to hours.
Is there an automatic PID optimiser?
Not at the moment. However the quick start guide will get you going quickly and the on-screen real time plot of the temperature error makes it easy to see how the control loop is working and optimise the values. We plan to add an automatic optimiser but are very protective of your valuable QCL!