B&R ECEP128-0 MULTI application memory

B&R ECEP128-0 MULTI application memory 

Material number:

ECEP128-0

Description:

MULTI application memory for type B CPUs and PPs 128 kB EPROM for 42 kB statements and 34 kB system module

All CAN interfaces from B&R are supplied internally, therefore CAN_V+ does not have to be

connected in CAN networks which do not contain devices from other manufacturers.

Branch Lines

Branch lines should be avoided if possible. However, it is possible to connect nodes to the bus

with a branch line as long as the distance is less than 30cm

Terminating Resistance

CAN networks are cabled using a bus structure where both ends of the bus are equipped with

terminating resistors.

9-pin DSUB Plug

For modules using a CAN interface, terminating resistor pins are assigned in the 9-pin DSUB

plug as shown in the following diagram

3. Grounding and Shielding Measures

In most applications, industrial controllers are installed in switching cabinets. Electromagnetic

switching elements (relays, contactors), transformers, motor controllers and frequency inverters

etc. are also found in these switching cabinets. Different kinds of electromagnetic interference

inevitably exist in such switching cabinets.

Generally this kind of interference cannot be avoided. However, if suitable grounding, shielding

and other protective measures are taken, the negative influence of the devices can be

considerably reduced. These protective measures include control cabinet grounding, module

grounding, cable shield grounding, protective circuits on electromagnetic switching elements,

and correct use of cables (choosing the proper cable cross section and type)

Grounding has essentially two different functions:

• Protective grounding

• Dissipation of electromagnetic disturbances

With the B&R 2000 controller generation both the dissipation electromagnetic disturbance and

the grounding is done through the mounting rail

3.1  Grounding the Mounting Rail

For grounding purposes, a good conductive connection between the mounting rail and the metal

back wall is required. The mounting rail is to be connected conductively to the back wall. This is

achieved by inserting a contact washer with the fastening screw

For lacquered or coated back walls, an adequate connection is only guaranteed if the screw has

been threaded into the back wall. If this is not the case, a contact washer must be must be placed

between the fastening nut and the backplane

3.2  Grounding Terminal Strip

It is advisable to mount a grounding terminal strip underneath the PLC. This should be

conductively connected to the screws of the control cabinet back wall. The cable shield and

module connections must also be attached to this grounding strip:

The distance between the grounding strip and the PLC is limited to a maximum of 15cm. No

electromechanical switching elements (relays, contactors, etc.) are allowed to be attached

between the PLC and the grounding strip. A cable duct is usually mounted directly below the

PLC. A grounding strip should also be used underneath bus expansions (I/O bus segments,

remoteI/O bus).

a ...... Metal, grounded control cabinet back wall

b ...... Conductive screw attachment to the control cabinet back wall

c ...... Grounding terminal strip

d ...... Mounting rai

Cable Shield Grounding

The following connections are made with shielded cables (possible exceptions are listed in the

individual module descriptions):

• Analog I/O

• Interface cables

• Encoder cables

The cable shield is to be grounded at both ends. On the PLC side, the grounding is made to the

terminal strip underneath the housing.

If any differences in potential exist between the PLC and connected elements, transient current

flows over the cable shield (often causes the cable to get warm), then the following steps should

be taken: The cable shield is to be separated and bridged with a high-quality capacitor (ceramic

or foil capacitors of at least 47nF with a low impedance at high frequencies).

DSUB connectors must be equipped with a metal-plated connector housing.

The shield is connected directly to the plug housing. Connecting the shield by twisting it before

attaching it considerably reduces the shielding effect and should therefore be avoided.

If metallic screw clamps are not available, the cable shield can be externally grounded with a

grounding clamp (see Section 3.3 "Cable Shield Grounding", on page 72)