Omron C1000H/C2000H PLC Practical Guide

2.6 I/O Remove Unit

C2000H unique features. Installed on racks that require online replacement of I/O units, it allows standard I/O units to be unplugged or inserted while the CPU is running (cannot be used for special I/O units). When using, the I/O unit of the rack needs to be "released" from the CPU control through a programmer, and then the terminal block and unit need to be physically disassembled. When replacing online, the output signal may generate short-term pulses, and attention should be paid to the influence of external devices.

2.7 Memory Pack

C1000H/C2000H uses a plug-in memory pack, which is inserted on the right side of the CPU. There are two types:

RAM package: readable and writable, data is held by the battery. Write protection switch (OFF=writable, ON=protective). Multiple models: 8K/16K/24K/32K characters.

ROM package: Using EPROM chips (27128, 27256, 27512150ns access time), data is permanently saved.

Special requirements for Duplex system: Two CPUs must be installed with memory packs of exactly the same specifications (with consistent capacity and write protection switch settings), otherwise a verification error will occur and the system cannot run. When using a RAM package to write a new program, the program on the active CPU will automatically write to the standby CPU (overwriting the original data).

Installation environment and mechanical specifications

3.1 Environmental conditions

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 and conductive dust

Vibration (mechanical durability) 10-25Hz, double amplitude 2mm, each axis lasting 2 hours

Vibration (electrical durability) 16.7Hz, double amplitude 1mm, 10 minutes on each of the three axes

Impact 98m/s ², 3 times in each direction

3.2 Installation direction and spacing

All racks must be installed vertically (text can be read normally). The CPU rack is located at the top, and the expansion rack is arranged in sequence below it.

The spacing between racks is 70-120mm for C1000H and C2000H Simplex systems, and 50-100mm is recommended for Duplex systems due to the large number of cables.

The total length of the extension cable shall not exceed 12m, and the maximum length of a single cable shall be 2m.

Install directly onto the control cabinet backboard, or use 35mm DIN rails (but rail installation has weak anti vibration ability, and it is recommended to fix it directly with screws in strong vibration environments).

3.3 Heat dissipation

Natural convection cooling does not require a forced fan, but if the temperature inside the control cabinet may exceed 55 ℃, a cooling fan must be installed.

Avoid installing PLC above heating equipment such as high-power transformers.

Ensure that the I/O cable layout does not block the heat dissipation holes.

3.4 Anti noise wiring

The distance between the I/O signal line and the high-voltage power line (>400V 10A or>220V 20A) must be ≥ 300mm; if they must be in the same cable tray, a metal partition with intermediate grounding should be used.

Use AWG14 (2mm ²) twisted pair shielded wire as the signal line.

The power line and signal line are laid separately in different cable trays/conduits.

The control cabinet should be reliably grounded (<100 Ω), and PLC grounding should not be shared with power equipment.

Power selection and current consumption calculation

This is the most error prone step in the installation of rack mounted PLCs. The 'available I/O current' of each rack power supply must be greater than the sum of 5V current consumption of all units on the same rack (including I/O units, special I/O units, link units, etc.).

4.1 Common I/O Unit 5V Current Consumption (excerpt)

Input unit:

3G2A5-ID112 (5-12V DC 16 points): 10mA

3G2A5-ID213 (12-24V DC 16 points): 20mA

3G2A5-ID215 (12-24V DC 32 point slow speed): 160mA

3G2A5-ID218 (12-24V DC 32 point fast): 260mA

3G2A5-ID212 (24V DC 64 point dynamic): 300mA

3G2A5-ID219 (24V DC 64 point static): 340mA

3G2A5-IA121 (100-120V AC 16 point): 180mA

3G2A5-IA222 (200-240V AC 16 point): 180mA

Output unit:

3G2A5-OC221 (relay 16 points): 100mA

3G2A5-OC223 (independent public 16 point): 100mA

3G2A5-OC224 (32 point relay): 200mA

3G2A5-OD411 (transistor 1A 16 points): 160mA

3G2A5-OD412 (transistor 0.3A 32 point): 230mA

3G2A5-OD212 (transistor 0.3A 32 point PNP): 230mA

3G2A5-OD213 (transistor 0.1A 64 point static): 460mA (+5mA/ON point)

3G2A5-OA121 (bidirectional thyristor 1A 16 points): 300mA

3G2A5-OA222 (bidirectional thyristor 1A 250V 16 point): 300mA

Special Unit:

3G2A5-CT001/012 high-speed counter: 330/550mA

3G2A5-PID01-E PID：1400mA

3G2A5-NC103-E Position Control 1 Axis: 1400mA

C500-ASC04 ASCII unit: 500mA

C500-LK009-V1 PC Link：900mA

C500-SNT31-V4 SYSMAC NET Link：1400mA

Link and Remote Unit:

3G2A5-LK010-(P)E I/O Link：600mA

C500-LK103(-P)/LK203 Host Link：1000mA

3G2A5-RM001- (P) EV1 optical remote master station: 700mA

4.2 Example of Current Calculation

A C1000H CPU rack uses PS221-E power supply (with available I/O current of 4A). Installation on the rack: CPU unit (approximately 1A), I/O control unit (approximately 0.3A), one ID218 (0.26A), one OD411 (0.16A), one OA222 (0.3A), one high-voltage meter CT012 (0.55A), and one Host Link (1.0A). Total ≈ 1+0.3+0.26+0.16+0.3+0.55+1=3.57A, less than 4A, feasible. But if another PID unit (1.4A) is added, it will exceed the limit.