garrettmace (Customer) asked a question.
I have the P1-04ADL-1 connected to a powered P1AM-100, which successfully reads measurements from an RTD module. I have external 24V wired to the P1-04ADL-1's 24V and 0V inputs. I have the same external 24V+ wired to my pressure sensors, which are then wired (through 32mA fuses) to the I+ inputs. I have measured current flowing through all of these loops with a multimeter, and the measurement is consistent with the expected pressure readings. I have measured voltage from COM to all of the I+ inputs, and the voltage is consistent with the measured current flowing through a 243 ohm resistor. I have verified that inside the P1-04ADL-1 module, when 24V is applied to the isolated analog domain, that isolated power supply is being powered and stepping down to a logic level supply voltage (5V).
The only thing that's not working: when I do a P1.readAnalog for that module's slot and input channels, it always read 0.
P1.check24V() reports that 24V is present (returns 0). P1.readStatus() for the 7th byte indicates that the readings are below range, which correlates to what I'm seeing.
Before trying to get a replacement, I would like to know how common this is (trying to spec it in a product, hard to access when built) and if there's any chance that a change on the P1-04ADL-1 module wasn't matched by a change in the P1AM-100 library.
Is the PLC in run mode?
It's a P1AM-100, there's no run mode. The same device reads a different module (RTD) just fine at the same time.
Hey @garrettmace (Customer) ,
Do you have a wiring diagram of your setup?
Are you able to provide your code, or at least the snippet relevant to the P1-04ADL-1?
There hasn't been any changes tot he P1-04ADL-1 that wasnt matched in the P1AM-100, so my guess is there may be an issue with the current setup.
Adam
Adam,
The wiring diagram is the same as the diagram in the instructional pamphlet. The code is based on the example code; it includes the library, waits for P1.init, then every three seconds performs a P1.readAnalog on the slot reported by P1.init. All channels are being used. The same setup also has an RTD module attached, which does report temperatures.
As in the pamphlet, the wiring is
Each input channel was also tested with a multimeter. I measured 8mA to 10mA passing through each of the input channels.
So I have verified approx 8mA passing through the I+ inputs of the module, but it continues to read 0. Not even any bit error in that measurement, but a solid 0.
Try this procedure to test the P1-04ADL-1 module.
Utilize a standard 1.5 volt battery (AAA, AA, C, or D). This provides a perfect source signal, since it's completely isolated.
1: Remove all existing signal wires
2: Connect the minus end of the battery to COM
3: Connect the positive end of the battery to an input channel
If the module is working the resulting reading should be around 6mA.
As above, I have already verified in-range current flowing into the I+ channels and am reading only 0 from the module.