# Slot 4 Menu 9 − Resources

Mode: Open‑Loop

Message Load

The Ethernet interface can accomodate multiple protocols running concurrently, each protocol demanding system resources. To ensure that the interface is not overloaded the following limitations should be followed.

1. maximum number of parameter accesses per second is 6000 (Unidrive M Ethernet interface) / 200 (SI-Ethernet on Unidrive M200 - M600)
2. maximum number of messages per second (02.004) is 8000

When checking that the message loading on a device is going to be acceptable, consider all protocols, e.g.:

Protocol | Number of Parameters | Rate | Parameters Accesses / Second | Message Rate / Second
Modbus TCP/IP | 10 read | 100 ms | 100 | 10
EtherNet/IP | 5 read | 10 ms | 500 | 100
| 5 write | 10 ms | 500 | 100
RTMoE | 2 write | 500 µs | 4000 | 2000
Total | 5100 | 2210
Max. supported on M700/M800 | 6000 | 8000
Within Capability? | Yes | Yes

Cyclic data, with the exception of synchronous cyclic data, is exchanged with the drive and other options in the interface's background task. Background cycles per second (4.09.008) can be used to view the cycle rate of the background task. If the value drops to zero then a BG Overrun drive trip will occur.

RTMoE

RTMoE is an industrial Ethernet protocol for both cyclic and acyclic communication. The Ethernet interface RTMoE capabilities can be found in the table below.

Capability | Support Level
Non-cyclic communication | Supported
Total transmit cyclic links | 5
Total receive cyclic links | 5
Max number of transmit synchronous cyclic links | 1 (Unidrive M interface only)
Max number of receive synchronous cyclic links | 1 (Unidrive M interface only)
Max length of non-synchronous cyclic link | 10 x 32 bit
Max length of synchronous cyclic link | 2 x 32 bit
Min transmission period | 500 µs
Synchronized with AMC | Yes (when cycle time >= 500us)
Synchronized with onboard program | Yes (when cycle time = 4ms)

Parameter | 4.09.001 Cyclic Tx Links Free
--- | ---
Short description |
Minimum | 0 | Maximum | 255
Default |  | Units |
Type | 8 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, ND, NC, PT, BU

The number of available transmit cyclic links.

Parameter | 4.09.002 Cyclic Rx Links Free
--- | ---
Short description |
Minimum | 0 | Maximum | 255
Default |  | Units |
Type | 8 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, ND, NC, PT, BU

The number of available receive cyclic links.

Parameter | 4.09.003 Fieldbus Links Free
--- | ---
Short description |
Minimum | 0 | Maximum | 255
Default |  | Units |
Type | 8 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, ND, NC, PT, BU

The number of available transmit / receive process images for fieldbus protocols such as Ethernet/IP.

Parameter | 4.09.004 Cyclic Mappings Free
--- | ---
Short description |
Minimum | 0 | Maximum | 255
Default |  | Units |
Type | 8 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, ND, NC, PT, BU

The number of available mappings in the system for use in cyclic links.

Parameter | 4.09.008 Background cycles per second
--- | ---
Short description |
Minimum | 0 | Maximum | 65535
Default |  | Units |
Type | 16 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, ND, NC, PT, BU

The background task cycles per second represents the number of times per second the background task is currently executing. The background task is responsible for cyclic data exchange with the drive. With more cyclic data mapped the cycle rate of the task will decrease.

Parameter | 4.09.010 Synchronous Task % Free
--- | ---
Short description |
Minimum | 0 | Maximum | 255
Default |  | Units | %
Type | 8 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, ND, NC, PT, BU

Note: Synchronous Cyclic Links are supported on (Unidrive M Ethernet interface) but not on (SI-Ethernet on Unidrive M200 - M600).

Parameter | 4.09.020 Synchronous Task Worst % Free
--- | ---
Short description |
Minimum | 0 | Maximum | 255
Default |  | Units | %
Type | 8 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, ND, NC, PT, BU

Worst case free resource of the synchronous task.

Note: Synchronous Cyclic Links are supported on (Unidrive M Ethernet interface) but not on (SI-Ethernet on Unidrive M200 - M600).

Parameter | 4.09.030 PCB Temperature
--- | ---
Short description |
Minimum | -128 | Maximum | 127
Default |  | Units | °C
Type | 8 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, ND, NC, PT