The PIC18F2455/2550/4455/4550 devices support multiple reset conditions to ensure reliable startup and fault recovery. Understanding the reset system is important for designing stable embedded applications.

The following table summarizes all reset events recognized by the device:

 register monitors and controls reset states. It contains status flags that indicate the reset source and includes control bits for interrupt priority and BOR functionality.

The reset system includes several internal mechanisms:

 Triggered by a VDD rise and coordinated with the PWRT (Power-up Timer).

 Triggered when voltage falls below the safe operating threshold.

 Ensures oscillator stability before program execution.

 Initiated when software fails to service the WDT within the required period.

A simplified block diagram in the datasheet illustrates the internal relationships among MCLR, PWRT, OST, INTRC, BOR, and related circuits.

Reset status flags remain set until cleared by firmware. A typical reset handling sequence is:

Determine the reset source based on the status flags.

Clear the relevant bits for subsequent reset detection.

POR = 0, BOR = 1 → Power-on Reset detected.

POR = 1, BOR = 0 → Brown-out Reset detected.

 after detecting a Power-on Reset to allow future POR event detection.

Reset flags may require manual clearing by firmware.

This document provides an overview of the reset subsystem and associated diagnostic behavior for the PIC18F2455/2550/4455/4550 family.

Power-Managed Modes

Reset System

EKKO

ASHE

MORDEKAISER

AATROX

CRISTI_TEST

PREG

FDAT

International Organization for Standardization, a global organization that promotes commercial and industrial standards.

15-digit electronic ID number associated with the animal eartag

BDAT

CDAT

DairyComp 305 - VAS Dairy Management Software

DC305

DRPC

oocyte

Breeding Code

In-Vitro Fertilization. In relation to embryo transfers, IVF occurs when oocytes (eggs) are collected via OPU (ovum pick up), and then in a lab, semen is added to create embryos.

oocytes

National Association of Animal Breeders. www.naab-css.org

NAAB

EDAY

RPRO

SIRC

ETDAM

Vet Code 6 = ABT? Often if a dairy sees a pregnant animal showing signs of heat they may breed her. When this breeding is entered in DairyComp the animal remains pregnant, but this flag is set so that the veterinarian can determine if she is still pregnant to the original breeding or if she has aborted and is now just another "bred status" cow.

Vet Code 6 = ABT?

Dairy cattle typically have their hooves inspected and, if necessary, trimmed every 4–6 months. A strategic hoof-trimming program might evaluate hooves before first calving, between 60 and 150 days in milk, and before dry-off.

TRIM

hoof trim

A combination of ingredients used to make feed for animals

recipe

The dry weight of an ingredient with no mositure

DM/HD

BNAME

CNTL

VISID

The value that appears most often in a set of data.

Mode

SCPEN

Tech

Mastitis is the persistent, inflammatory reaction of the udder tissue due to physical trauma or infection. Symptoms of mastitis include udder swelling, heat, hardness, redness, or pain. The milk may have a watery appearance, flakes, clots, or pus.

Mastitis

mastitis

Metritis is inflammation of the wall of the uterus, and usually occurs within days of calving. Symptoms of metritis are an enlarged uterus and a foul-smelling uterine discharge.

metritis

Pneumonia is lung inflammation caused by a bacterial or viral infection. Early symptoms may include fever, depression, reduced appetite, nasal and eye discharge, salivation, shallow breathing, and soft coughing.

Pneumonia

Lameness includes any abnormality which causes an animal to change the way it walks, and can be caused by a range of foot and leg conditions, including hoof ailments, hock damage, bruising, sores, or cuts.

Lame

Diarrhea in young animals. Scours causes dehydration in calves and is the leading cause of death in calves under one month of age.

Scours

Retained placenta is the failure to expel fetal membranes within 24 hours after parturition. The primary symptom of a retained placental is degenerating, discolored, and ultimately fetid membranes hanging from the vulva.

Retained Placenta

Ketosis is a common ailment that usually occurs in early lactation, when the energy demands of milk production are very high and the cow metabolizes fat stores for energy. Symptoms of ketosis may include reduced milk yield, weight loss, reduced appetite, acetone smell of breath and/or milk, and fever.

Ketosis

Milk fever is a disease characterized by reduced blood calcium levels. It occurs in early lactation, when demand for calcium for colostrum and milk production exceeds the cow's ability to mobilize calcium. "Fever" is a misnomer, as body temperature during the disease is generally not elevated. Milk fever symptoms include tremor in the muscles of the head and limbs until falling to a "sitting" position. Once down, cows may have a dry muzzle, staring eyes, cold legs and ears, constipation, and drowsiness.

Milk Fever

Displaced abomasum in cattle occurs when the abomasum, also known as the true stomach, which typically resides on the floor of the abdomen, fills with gas and rises to the top of the abdomen, where it is said to be "displaced". Symptoms may include reduced appetite, lower milk yield, reduced rumination, and a distended abdomen.

Displaced Abomasum

EDAT

retained placenta

KPIs

The term "Zone" represents different dairy locations. Platform Zones may be different physical dairy locations (for example, multiple locations across the state or country) or different user-defined locations within a single dairy site (for example, Pens 1-100 are Zone 1, Pens 101-200 are Zone 2, etc.).

Zone

Allows you to manage the dairy's billing account for the VAS PULSE Platform.

Billing Management

Allows you to create new Dairy Dashboards and customize the widgets displayed on existing ones.

Dashboard Management

Dashboard View

Allows you to upload, download, and manage shared files, including the ability to create, edit, delete, and view file history details, in any domain.

File Management

Allows you to download and view history details for general shared files not associated with Herd, Feed, and Parlor data.

General

Allows you to manage Platform integration with other applications that send data to or extract data from Platform (for example, DairyComp for DC Unlimited subscribers, FeedComp, Parlors, and other allowed 3rd‑party software integrations).

Integration Management

Allows you to edit the dairy profile settings under Dairy Configuration > Dairy Information (dairy description, discoverability, address, etc.).

Profile Management

Allows you to invite new users, remove existing users, and manage role and permission settings for other users.

User Management

Allows you to create and manage dairy Zones. The term "Zone" represents different dairy locations. Platform Zones may be different physical dairy locations (for example, multiple locations across the state or country) or different user-defined locations within a single dairy site (for example, Pens 1-100 are Zone 1, Pens 101-200 are Zone 2, etc.).

Zone Management

Allows you to adjust dry matter % in FeedComp.

Adjust DM%

Allows you to manage Inventory in FeedComp.

Access

Mobile App Access

Allows you to edit Pen Counts in FeedComp.

Counts

Allows you to edit Pen Feeding Amounts in FeedComp.

Feeding Amounts

Allows you to edit Ingredient Amounts in FeedComp.

Adjust  Amounts

Allows you to set Alternate Recipes in FeedComp.

Set Alternate

recipes

TOTM

TOTF

Total protein/solids not fat this lactation

TOTP

305ME

dry matter

Standard Send File. This is a text file with animal event and production information used to provide data to a dairy records processing center (DRPC).

Standard file created by a dairy records processing center (DRPC) that includes the latest status information for each animal in the herd.

Dairy protocols include a series of treatments or tasks that follow a prescribed order and schedule. Protocols may be defined for reproduction purposes, to treat an illness, or for routine vaccinations.

Protocols

TODAY

XID is short for "Change ID", as in changing an animal's ID number.

SIR1

SIR2

SIR3

Embryos are harvested by being flushed out of a superovulated cow that has already been bred.

embryo flush

EAGE

Reproductive code = 2 (FRESH). Used to identify animals that have recently given birth ("fresh").

RC=2

Reproductive code = 3 (OK/OPEN). Used to identify animals that are eligible to breed. These could be fresh animals that were checked and declared ready to breed or a bred animal that was declared open.