---
title: "MonitorPass"
description: "one pass of the beat that runs the armed monitors: every armed version read, the units of its place's population evaluated since the monitor's last answer, a catch written for each unit admitted at an observation not caught before, a signal ranked from each catch, and the monitor's last answer kept"
section: concepts
address: /concepts/monitorpass
contract: 0476e35e6e275db5
---

# MonitorPass

one pass of the beat that runs the armed monitors: every armed version read, the units of its place's population evaluated since the monitor's last answer, a catch written for each unit admitted at an observation not caught before, a signal ranked from each catch, and the monitor's last answer kept

[figure: MonitorPass is a work at platform scope. The drawing shows its fields and the objects that they point at.]

| property | value |
|---|---|
| kind | work |
| scope | platform |
| key | the beat's tick |
| store | postgres |
| family | rules_engine |



## Fields


| field | type | required | note |
|---|---|---|---|
| `monitors` | `count` | yes | the armed versions run |
| `units_read` | `count` | yes |  |
| `catches` | `count` | yes | new catches |
| `signals` | `count` | yes | new signals |
| `not_evaluable` | `count` | yes | readings no condition could judge |
| `deferred` | `count` | yes | left for the next tick by the beat's budget |
| `tenants_served` | `count` | yes |  |
| `at` | `time` | yes |  |



## Routes that use it
No route takes or returns MonitorPass directly. The record holds it, and the objects that point at it reach it.