Home/Support/Support Forum/AIO adapter doesn't return expected values for current loop without 250ohm resistor to ground.

AIO adapter doesn't return expected values for current loop without 250ohm resistor to ground.

0 votes
I thought there was supposed to be an internal resistor for the purpose of measuring the voltage drop for analog conversion.

I've verified the sensor is returning the expected 4ma but I get a valued from the AIO of 540. I would expect to see around 175 given the formula from the Digi python libraries.

Does the internal resistor not exist in all hardware versions or does it need to be enabled through a specific config/firmware?

Here is my current config for the AIO.

Configuration of device:

aggregation (AR): 255 (x 10 sec)
assoc_led (LT): 0 (x 10 msec)
broadcast_hops (BH): 0
cluster_id (CI): 0x11
conflict_reports (CR): 3
dest_addr (DH/DL): <my connect port x2>
dest_endpoint (DE): 0xe8
dio0_config (D0): 2
dio1_config (D1): 2
dio2_config (D2): 2
dio3_config (D3): 2
dio4_config (D4): 4
dio5_config (D5): 1
dio6_config (D6): 4
dio7_config (D7): 4
dio8_config (D8): 4
dio10_config (P0): 4
dio11_config (P1): 3
dio12_config (P2): 4
dio13_config (P3): 5
dio_detect (IC): 0x0 (bitfield)
discover_timeout (NT): 60 (x 100 msec)
encrypt_enable (EE): 0
encrypt_options (EO): 0x0 (bitfield)
ext_pan_id (ID): 0x0000000000000000
join_time (NJ): 255 (sec)
join_notification (JN): 0
join_verification (JV): 0
link_key (KY):
max_hops (NH): 30
network_watchdog (NW): 0 (min)
node_id (NI): Well Monitor
polling_rate (PO): 0 (x 10 msec)
power_level (PL): 4
power_mode (PM): 1
pullup_enable (PR): 0x1fff (bitfield)
rssi_timer (RP): 40 (x 100 msec)
sample_rate (IR): 10000 (msec)
scan_channels (SC): 0x3fff (bitfield)
scan_duration (SD): 3 (exponent)
sleep_count (SN): 1
sleep_mode (SM): 0
sleep_options (SO): 0x0 (bitfield)
sleep_period (SP): 32 (x 10 msec)
sleep_time (ST): 5000 (msec)
source_endpoint (SE): 0xe8
stack_profile (ZS): 0
supply_threshold (V+): 2000 (mvolts)
wake_host_delay (WH): 0 (msec)
asked Jul 26, 2015 in ZigBee PRO Featureset (and legacy ZNet 2.5) by acervantes New to the Community (0 points)
recategorized Jul 21, 2015 by michaelt
Did you ever get this worked out?  i'm having a similar problem and have had no luck figuring it out.  I'm receiving a reading of over 20mA from my xbee adapter at the gateway but when I test the circuit with a meter I am seeing 4mA being produced... Help please!
I haven't found any way of getting an accurate value without that resistor.  It's not a huge deal but I would have liked to see that in the documentation.  This seems to be an unsupported legacy product.

Please log in or register to answer this question.

1 Answer

0 votes
Most modules have an internal pull up and pull down resistor that you can control. From the sounds of it, you don't have that pins pull up enabled.
answered Sep 14, 2015 by mvut Veteran of the Digi Community (15,223 points)