Honeywell IPC 620-06 Programmable Controller

Honeywell IPC 620-06 Programmable Controller

Introduction

In the development of industrial automation, the Honeywell IPC 620 series programmable logic controller (PLC) became one of the core control devices for factory automation in the late 1980s to mid-1990s due to its modular design, powerful communication capabilities, and high reliability. The IPC 620-066 processor system (model 620-0636) is a high-performance single slot processor in this series, supporting up to 192 I/O points, multiple communication options, and online programming functions. It is widely used in packaging, material handling, metal processing, and process control fields. This article is based on Honeywell's official "IPC 620 Programmable Controller Model IPC 620-06" technical manual (form number 620-8975), which fully restores the technical details of this classic PLC system from five dimensions: hardware architecture, system configuration, operating principles, instruction system, and diagnostic maintenance.

Hardware Architecture: Modularity and Scalability

2.1 Selection of Processor Rack and Chassis

The IPC 620-06 system uses a dedicated processor rack and offers four models to meet different installation requirements:

Model Name I/O Slot Number Characteristics

620-0090 standard full-size rack with 8 supports I/O expansion modules and option modules

620-0091 Enhanced full-size rack with 8 additional upper layer local buses, supporting dual bus communication (such as servo modules)

620-0092 standard half size rack 4 without expansion module and option module slots

620-0093 Enhanced Half Size Rack 4 with Upper Local Bus

All racks comply with the "HE" standard and can be installed in 19 inch cabinets or panels through reversible brackets. The connector adopts anti misalignment design to prevent module reverse insertion.

2.2 Processor Module (PM) 620-0636

The processor module is the core of the entire system, using Motorola 68B09E microprocessor, onboard 2K program memory (expandable), and includes the following key features:

Memory and registers: Output status table 768 bits (0-767), where 0-191 is the actual I/O output and 192-767 is the control relay; There are 256 addresses in the 16 bit register area, ranging from 4096 to 4351.

Battery backup: Built in AA type 3V lithium battery, supporting memory and register data retention for at least 6 months. The front of the module is equipped with a battery compartment and a "BATTERY PASS" indicator light. Attention: Lithium batteries are strictly prohibited from being air shipped, short circuited, overcharged, burned, or punctured.

EPROM extension: onboard U32 socket, supporting 27128 EPROM as a permanent backup for user programs. When powered on, the processor automatically copies the contents of the EPROM to RAM and determines whether to retain the output status table and register data based on the battery status.

DIP switch configuration: The processor interface board (SW1) and MPU board (SW1, SW2) have three sets of 8-bit DIP switches, which are used to set the forced function (FORCE), battery low voltage start suppression, online programming permission, output fault response, and processor rack I/O slot capacity (0/8/16/32 points). The specific setting method can be found in the appendix.

2.3 Power Supply Module (PSM)

The system supports multiple power modules, which are used for processor racks and I/O racks respectively:

Processor rack dedicated power supply (full-size)

620-0041:115/230VAC switchable, providing 8A@5VDC +600mA @ ± 15VDC, power consumption 95VA, surge 15A/cycle.

620-0083:115/230VAC toggle switch, provided 15A@5VDC +1.16A @ ± 15VDC, total output ≤ 90W, power consumption 110VA, surge 20A/cycle.

620-0046:24V DC input (20-28V), 8A@5VDC +600mA @ ± 15VDC, power consumption 96VA, surge 40A.

I/O rack/half size processor rack power supply

621‑9932：24VDC， 8A@5VDC +600mA @ ± 15VDC, single slot width.

621‑9933：115/230VAC， Double slot width, 10-- 15A@5VDC +1.3-2A @ ± 15VDC, the output characteristics are shown in the derating curve in Figure 4.

621‑9934：115/230VAC， 8A@5VDC +600mA @ ± 15VDC, single slot width.

All power modules are equipped with front-end replaceable fuses and 5VDC green LED indicator lights. 230VAC operation requires replacing the corresponding specification fuse and adjusting the voltage selection switch/short circuit board.

2.4 I/O System and Expansion

The IPC 620-06 adopts the 621 parallel I/O system, supporting 8, 16, and 32 point digital modules as well as various analog and special function modules. The I/O rack is divided into full-size (12 slots) and half size (6 slots), and is connected to the processor rack through the I/O expansion module (IOEM) 620-0053. The parallel link uses 50 core D-type cables, with a maximum total length limit of 50 feet. It adopts a daisy chain topology and can connect up to 2 I/O racks (achieving 192 point I/O).

The parallel I/O module (PIOM) 621-9937 is the interface and control core of the I/O rack, replacing the early model 621-9930. Each I/O rack must be equipped with a PIOM, which includes the following functions:

Decoding the address data sent by the processor to generate chip selection signals corresponding to the slot positions;