Omron C500 PLC Installation and Maintenance Guide

Omron C500 PLC Installation and Maintenance Guide

System Overview and Applicable Scenarios

Omron C500 is a classic rack mounted programmable controller widely used in industrial automation systems from the late 1980s to the 1990s. Although it has been replaced by new models, there are still a large number of equipment in operation in a large number of old production lines, ship control systems, and infrastructure projects. Mastering the hardware installation, power configuration, I/O unit selection, and maintenance methods of C500 has high practical value for ensuring the stable operation of existing systems and rapid fault repair.

The C500 adopts a modular rack structure, consisting of a CPU rack and up to three expansion I/O racks, with a total of 512 I/O points. Its core components include: backplane, power unit, CPU unit, I/O unit (input/output), special function unit (such as analog, high-speed counting, position control), communication unit (Host Link, PC Link, SYSMAC NET Link), and remote I/O unit. This article is based on the official hardware installation manual and provides a complete set of operation guidelines for common needs of on-site engineers.

System composition and model identification

2.1 Backplane

C500 has multiple backplane models for installing CPU, power supply, and I/O units. The backplane provides I/O slots from left to right, with the rightmost slot typically used for power units, and some backplane rightmost slots also support link units.

Backboard model, I/O slot number, link slot location, applicable scenarios

C500-BC091 has a maximum configuration of 9 I/O slots and 5 link slots, requiring a large amount of I/O

3G2A5-BC081 8 I/O slots 3 link slots Conventional CPU rack

C500-BC082 requires multiple link units for 8 I/O slots and 5 link slots

C500-BC061 6 I/O slots 5 link slots Medium configuration

3G2A5-BC051 5 I/O slots 3 link slots Compact CPU rack

C500-BC052 5 I/O slots 5 link slots Link unit priority

C500-BC031 Minimum configuration of 3 I/O slots and 3 link slots

The expansion I/O rack uses dedicated backplanes: 3G2A5-BI081 (8 slots) and 3G2A5-BI051 (5 slots), which require separate configuration of power and I/O interface units.

2.2 CPU Unit

The C500 CPU model is C500-CP11-V1, which does not come with a power supply and memory pack. It requires an additional power supply and memory pack (RAM or ROM). The front panel of the CPU provides:

Peripheral connector (direct insertion programmer)

Memory pack slot (located on the left side)

Run/Stop Switch

Status indicator lights (POWER, RUN, ALARM, BATT LOW)

2.3 Power Supply Unit

The power unit is installed on the far right side of the rack (some of the rightmost slots on the backplane also allow for the installation of link units, and the power supply needs to be installed in another dedicated location). The power supply provides 5V DC to all units on the backplane, and some models also provide 24V DC service power.

Model Input Voltage 5V Output Capacity Can be used for I/O Unit Current 24V DC Output

3G2A5-PS221-E 100-120/200-240V AC (switchable) 7A 5A 0.8A

3G2A5-PS223-E 24V DC 12A 10A None

C500-PS213-E 24V DC 9A 5A None

3G2A5-PS222-E 100-120/200-240V AC 7A 6.5A 0.8A (for expansion rack)

3G2A5-PS212-E 24V DC 7A 6.5A None

Key point: The nominal output capacity of the power unit is different from the actual current available for the I/O unit. For example, PS221-E outputs 7A, but 2A has already been consumed by the CPU and backplane itself, and only 5A is actually available for the I/O unit. When designing the system, the 5V current consumption of all I/O units, special units, and link units installed on the same rack must be added up and not exceed the "available current" of the rack power supply.

2.4 I/O Control Unit and I/O Interface Unit

I/O control unit (3G2A5-II101): must be installed on the leftmost side (first I/O slot) of the CPU rack for connecting to the expansion I/O rack. Even without expansion, it can still be installed (retaining future expansion capabilities).

I/O Interface Unit (3G2A5-II002): Each expansion I/O rack must have an I/O interface unit installed in its leftmost I/O slot for communication with the I/O control unit of the CPU rack.

Installation environment requirements

The C500 PLC must be installed in a control cabinet that meets the following conditions, otherwise it may cause malfunctions or shorten its lifespan:

Parameter requirements

Operating at an ambient temperature of 0-55 ℃ and storing at -20~65 ℃

Humidity 35%~85% RH, no condensation

Altitude ≤ 2000m

Pollution without corrosive gases, conductive dust, metal powder

Vibration of 10~55Hz, double amplitude of 0.5mm (direct installation); 16.7Hz， Double amplitude 1mm (DIN rail installation)

Impact 10G, 3 times in the downward direction

The installation direction is vertical, and the text can be read normally. The CPU rack is located above, and the expansion rack is located below

Rack spacing of 70-120mm, convenient for heat dissipation and wiring

The total length of the extension cable between each rack is ≤ 12m, and the length of a single cable is ≤ 2m

Heat dissipation design:

Maintain sufficient clearance between racks (≥ 70mm).