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Questions
New design, sensors selection
Hello everyone,
I'm new to the IQAN ecosystem but I want to start using it.
My first project will be a scissors lift platform mounted on a vehicle on top of a mobile workshop.
Since this platform require EN280 safety compliance, I plan to use MC43FS and XC43 units together with MD5-5 display and G12 module.
All safety relevant sensors and controls need to be redundant.
I need to understand which type of sensors to use with respect to the ease of implementation vs. performance.
Most of the sensors are now CANopen devices, with a lot of advantages (safety, resolution/precision, ease of hardware connection...) but not easy to implement in IQAN Design (at least for me now). (but I have PCAN + PCAN Explorer6, CAN analyser from GEMAC, CANTouch)
On the other hand, voltage output sensors are easy to implement in IQAN. (0.5-4.5V ratiometric, redundant or two separate sensors)
Most systems use 4-20mA sensors but the IQAN modules don't have so many inputs ( 2 or 4 ).
In my design, the cable length between the IQAN module and a sensor will be maximum 6m.
Which sensors type to choose? (always redundant sensor, or two sensors with two signals for safety relevant signals)
a. voltage sensors - more influenced by external interference.
b. 4-20mA sensors with 250ohm(0.1%) pull down resistors ???
c. CAN J1939, easyer to implemet than CANopen.?
d. CANopen, dificult to implement.
Customer support service by UserEcho
Ratiometric 0.5-4.5V sensors is a good choice for MC43FS/XC43, there are plenty of inputs on the controllers.
4-20 mA also works, I would recommend connecting to the dedicated current loop inputs on MC43FS/XC43. Then there is no need to add external pull-down. Number of current loop inputs may be a limiting factor.
For CAN sensors used in safety functions, look at sensors supporting SAE J1939-76.
This is easy to implement in IQAN using the JFSIN channel, and the J939-76 protocol complies with functional safety requirements on bus protocols.
Thanks for your reply, Gustav.
Then I will use a combination of sensor types. Tilt and rotation sensors will be ratiometric 0.5-4.5V (and/or CAN J1939-76), hydraulic pressure sensors will be 4-20mA (and maybe ratiometric 0.5-4.5V to avoid external pull down resistors). I need eight pressure sensors which I want to connect on the master unit MC43FS.