Siemens OSM, ESM technical specifications Latency, Link Control, TP Port

Glossary

Latency	The latency specifies the taken for packets to pass through the
	OSM/ESM. It is assumed that a received packet can be sent on
	immediately. The latency does not include the time necessary for the
	OSM/ESM to receive a packet.
Link Control	OSMs/ESMs monitor the connected TP/ITP cable segments for short-
	circuits or wire breaks using regular link test pulses complying with the
	100BASE-TX standard. OSMs/ESMs do not send data to a segment
	from which they are not receiving link test pulses. An unused interface
	is taken to be a wire break since the device without power cannot send
	link test pulses.
MDI-X	Medium Dependent Interface Crossover
	RJ-45 jack with pinning of a network component
OSM	Optical Switching Module. SIMATIC NET Ethernet switch with optical
	and electrical ports

Reconfiguration Time Time required by the OSM/ESM operating in the redundancy manager (RM) or standby mode to reestablish a functioning configuration if a device fails or the cable is interrupted.

Redundancy Manager Mode of an OSM or ESM for forming a redundant ring structure. The

(RM)RM monitors the OSM or ESM bus connected to it, closes the bus if it detects and interruption. This reestablishes a functioning bus configuration.

One and only one device can operate in the RM mode in every OSM or

ESM ring.

Signaling Contact Floating relay contact via which the error states detected by the OSM/ESM can be signaled.

Standby-sync port Port of an OSM/ESM via which two OSMs or ESMs are interconnected in a redundant ring link allowing them to inform each other of their operating states (not available with the OSM TP22 and ESM TP40).

Store and forward In this switching method used on the OSM/ESM, the complete packet is read in before it is passed on by the switch. A packet is only passed on if it is error-free.

TP Port Port with a TP connector (RJ-45 jack)

Industrial Ethernet OSM/ESM	89
C79000-Z8976-C068-10