Description
The 216EA61 input unit receives the analogue measured variables from the 216GW61 input transformer module, digitises
them and transfers them to the B448C bus.
The unit has 24 analogue I/P channels, i.e. a maximum of two
216GW61 input transformer modules can be connected to a
216EA61 I/P unit (see also Section 2.6.1.).
connector “a” (upper) : channels CH01…CH12
connector “b” (lower) : channels CH13…CH24
Within the protection system, the designations of the O/P channels correspond to those of the I/P channels. Where a system
requires several 216EA61 units, the measurement channels are
designated within the system according to Table 2.1.
Design
Figure 12.8 shows the front view of the 216EA61 I/P unit, which
is a plug-in unit with a width of 2 standard divisions (2T). The internal auxiliary supply voltage is 5 V and is derived inside the
unit from the 24 V auxiliary d.c. supply. The unit’s main components are:
a 24 (measurement) channel analogue (-40 V…+40 V)-todigital converter
a processor for pre-processing the measured variables
(80C186)
a bus interface (64 kByte DPM/RAM)
a program memory (128 kByte EPROM)
a main memory (64 kByte RAM)
an electrically deletable and programmable data memory
(8 kByte EEPROM).
Frontplate signals and controls (see Fig. 12.8)
LED “ALARM” (red):
Lights when the unit has an internal defect. See Section 6.1.
for possible causes.
LED “MST” (yellow):
Master. Lights when the unit communicates with the bus and
exchanges data. (May light only briefly or flash.)