The Siemens 6AG1055-4MH00-2BA0 is a spare-part SIPLUS LOGO! TD display based on the 6ED1055-4MH00-0BA0 with conformal coating, now classified as obsolete. It runs a 4-line STN display with LED backlight, carrying a front IP40 rating and 10 configurable system keys. The unit connects to all LOGO! basic units from 0BA6 onward via a 2.5 m cable.
Against the standard LOGO! TD — 6ED1055-4MH08-0BA1
The active peer 6ED1055-4MH08-0BA1 carries a wider ambient range of -40 to +70°C and an IP65 front, but it trades the 10 configurable system keys for a sealed front with no keys, and its FSTN display runs 6 lines of 20 characters against the 4×24 on this unit. The compatibility shift from LOGO! 0BA6 to LOGO! 8 and higher means that swapping the display will require a firmware revision on the basic unit; the mechanical footprint remains identical (86×128.2×38.7 mm), so re-paneling isn't needed, but the program logic that relied on the 10 system keys must be rewritten for a keyless interface.