The modular safety system ESM-F
Plug-in and use! – The advantages of the modular system
Connecting several modules in series using the ESM-F system does not involve any wiring effort. The units are connected together using a special connector system and are ready for use immediately. Programming is not necessary.
To be able to work with the system, it is first necessary to connect a base unit. The input modules are positioned to the left of the base unit and the output modules to the right. In this way it is easy to expand the system.
By simply connecting together the units, it is possible to implement any combination of non-time-delay and time-delay safety contacts. The number of expansion units is almost unlimited.
The uniform and space-saving design of all the devices in the entire series also makes possible installation in compact control cabinets
Quick troubleshooting
Every ESM-F unit is equipped with LEDs that indicate the device status and the state of the inputs and outputs. The safety devices are connected using plug-in connection terminals that can be rapidly disconnected from the device. A faulty unit can be replaced quickly. The faulty unit is simply removed and replaced with a new unit – that's it! Function is restored immediately.
Automatic or manual start
The base unit can be started either manually using a start button or automatically.
Monitored, manual start
Un-monitored, manual start
Automatic start
Contacts for higher currents and feedback loop
To be able to use contacts that are suitable for higher currents, the safety contacts on the device can be extended using external contactors with positively driven contacts.
The coils on the contactors are operated using the safety contacts on the base unit or on an output unit and the monitoring contacts on the contactor are monitored by the feedback loop inputs on the ESM-F unit.
Setting up safety groups
Safety groups can be formed using the ESM-F system. In this way it is possible to shutdown only that part of the system in which maintenance or setup work is to be performed. All remaining parts of the system continue to function.
A dedicated base unit is used for each group. In this way each group can be evaluated separately. By simply connecting the groups of units in a specific manner, it can be achieved that certain safety components only act on one base unit, while other safety components, e. g. emergency stop buttons, are transferred to the entire system.
The logical allocation is realized using a twin cable. Here the group outputs (GO1 and GO2) for a higher level base unit or input module are fed to the group inputs (GI1 and GI2) on a base unit in a different group. The signal GO on the input module drops out as soon as a safety path is interrupted on either this or any other input module to the its left.
The higher-level input module then acts on this group. The example given shows the correct allocation of the units and the connection of the connection cable:
The function of the outputs GO1 and GO2 on the base unit is similar. However, here the signal GO is only affected by the inputs S12 and S14. The following application examples show the difference.
- Forming a group with the outputs GO1 and GO2 on an input module
Formation of a group with input units and base units
The input modules In1 and In2 shut down the output modules in both groups, input module In3 only acts on group 1. The units In4 and In5 only on group 2. The connection cable is connected between the terminals GO on the last input module on the right that is to act on all groups (here: In2), and the terminals GI on the base unit for group 2 (base 2).
Using the ESM-F system it is also possible to form more than two groups. A wide range of combinations of input modules can be allocated to each group.
- Forming a group with the outputs GO1 and GO2 on a base unit
It is also possible, e.g., to connect daisy-chained emergency stops to a base unit and for only this chain to act on other base units. The following example shows such an application. Only the inputs S12 and S14 on a base unit act on the outputs GO1 and GO2.
In this way it is possible for the emergency stop chain to act on both base units, while the safety inputs S22 and S24 and all input modules in the group only act on base unit 1.
Formation of a group with two base units. Example connection for daisy-chained emergency stops
Adding time-delayed outputs
Sometimes it is necessary to continue to supply parts of the system with power after an emergency stop request, e. g. to move tools to a safe home position or to brake parts of the system that run on. In this case a turn-off delayed unit is used on the right beside the standard output modules. This additional unit switches off its four safety contacts after the time-delay set on the potentiometer has elapsed (controlled stop, stop category 1 in accordance with EN 60204-1).
A special advantage is the ease with which time-delayed outputs can be added: if more than four time-delay contacts are required, it is possible to fit further standard output module to the right of the turn-off delayed output module; these additional standard output modules are then switched at the same time as the turn-off delayed module.
If several different time-delays are required, the system can be expanded with further turn-off delayed output modules. All time-delayed output units are independent of the time-delayed outputs positioned to the left. In the above example it is also possible for T2 to be less than T1.