Difference between SEN_0V_A1 and SEN_0V_B1

[dotmat]

Hi All,

I'm getting to grips on the wiring of the M142 for a diesel project.
Looking at the wiring doc from the PDF it has;

A33 SEN_0V_B1 Sensor 0V B
A34 SEN_0V_A1 Sensor 0V A

B26 SEN_5V0_A Sensor 5.0V A

C02 SEN_5V0_A Sensor 5.0V A
C09 SEN_5V0_B Sensor 5.0V B

D15 SEN_0V_A Sensor 0V A
D16 SEN_0V_B Sensor 0V B

D03 AT1 Analogue Temperature Input 1 1k Pull up to SEN_5V_A
(not all pins listed for brevity)

Given the A,B,C context. I'm assuming it's an 'A', 'B' and 'C' circuit where all the A's connect, all the B's connect etc.
In the case of D03 the circuit is part of 'A' so an analog temperature input (using 3 pin sensor) would make use of:

C02 SEN_5V0_A Sensor 5.0V A -> This is the 5V
D15 SEN_0V_A Sensor 0V A -> This is the low/gnd
D03 AT1 Analogue Temperature Input 1 -> This is the signal line.

Have I got this right?
Thanks for any help.
Mathew

[Stephen Dean]

Hi Mathew,

The AT's are internally connected through a 1K pullup to their matching 5V0 rails, so AT_1 and AT_2 are linked to 5V0A , AT_3 and AT_4 to 5V0B and AT_5 and AT_6 to 5V0C. The Analogue Temperature sensors use the matched 0V rails.

So for an Analog Temp sensor you would wire it this way.

D15 SEN_0V_A Sensor 0V A -> This is the low/gnd
D03 AT1 Analogue Temperature Input 1 -> This is the signal line.

The 5V and 0V supplies can be shared between multiple sensors.

[faustohawkins]

Hi Mathew,

The AT's are internally connected through a 1K pullup to their matching 5V0 rails, so AT_1 and AT_2 are linked to 5V0A , AT_3 and AT_4 to 5V0B and AT_5 and AT_6 to 5V0C. The Analogue Temperature sensors use the matched 0V rails.

So for an Analog Temp sensor you would wire it this way.

D15 SEN_0V_A Sensor 0V A -> This is the low/gnd
D03 AT1 Analogue Temperature Input 1 -> This is the signal line.

The 5V and 0V supplies can be shared between multiple sensors.

Hello

if 5V and 0V supplies are shared between multiple sensors, wouldn't that cause a drop in voltage?

[Stephen Dean]

There will only be a drop if the sensors exceed the current capacity of the outputs, a sensor failing or if a sensor is wired incorrectly. I have (for testing purposes only) run enough sensors to use up all of the available inputs on an M150 off of a single 5V supply, and I did not record a drop in the voltage supplied.