Specifications

Chapter 2 – Hardware Resources
18 PL 3120/PL 3150/PL 3170 Power Line Smart Transceiver Data Boo
k
When the PL Smart Transceiver is not within the specified power supply voltage range, a pending or on-going
EEPROM write is not guaranteed. The PL Smart Transceiver contains a built-in low-voltage interruption (LVI) circuit
that holds the chip in reset when V
DD5
is below a certain voltage. See the PL 3120/ PL 3150 or PL 3170 Smart
Transceiver Datasheets for LVI trip points. This reduces the risk of EEPROM data corruption. For PL 3150 Smart
Transceiver devices with external flash memory an external pulse stretching LVI is required. See RESET Pin for more
information on LVI circuitry.
In the event of a fault, the on-chip EEPROM of the PL 3150 Smart Transceiver can be reset to its factory default state by
executing the EEBLANK program. To do so, program the appropriate EEBLANK file into an external memory device,
temporarily replace the application’s external ROM or flash with the chip that has EEBLANK loaded, and power up the
device. The EEBLANK files are named eeb<n>.nri where <n> is the Neuron input clock rate in kHz and is one of the
following: 20000, 10000, 05000, 02500, 01250, or 00625. If you are using an input clock between two of these speeds,
select the next slower version of EEBLANK.
After around 20 seconds (or less depending on clock speed), the device’s service LED should come on solid, indicating
that the EEPROM has been blanked. Then replace the original application ROM or flash. The EEBLANK files are
distributed with NodeBuilder 3.1 and Mini EVK Evaluation Kit software. Versions of EEBLANK distributed with prior
releases of the LonBuilder
®
and NodeBuilder tools should not be used with the PL 3150 Smart Transceiver.
The set_eeprom_lock() function can also be used for additional protection against accidental EEPROM data
corruption. This function allows the application program to set the state of the lock on the checksummed portion of the
EEPROM. Refer to the Neuron C Reference Guide for more information.
The internal EEPROM of a PL Smart Transceiver will contain a fixed amount of overhead and a network image
(configuration), in addition to user code and user data. The following table shows the maximum amount of EEPROM
space available for user code and user data assuming a minimally-sized network image. Also shown is the minimum
segment size for user data. Constant data is assumed to be part of the code space.
Table 2.6 Memory Usage
Device Firmware Version
EEPROM Space
(Bytes)
Segment Size
(Bytes)
PL 3120 Smart Transceiver 14 3969 8
PL 3170 Smart Transceiver 17 3964 8
PL 3150 Smart Transceiver 14 or newer 384 2
EEPROM must be allocated in increments of the device's segment size, the smallest unit of EEPROM that can be
allocated for variable space. For example, if there are three 3-byte variables used, there must be 9 bytes of variable
space. For a PL 3120 or PL 3170 Smart Transceivers, this would result in the allocation of 16 bytes for variable space,
as 16 bytes is the lowest increment of the device segment size (8 bytes) that can store the three 3-byte variables. For a
PL 3150 Smart Transceiver, this would result in the allocation of 10 bytes for variable space, as 10 bytes is the lowest
increment of the device segment size (2 bytes) that can store the three 3-byte variables.