Rockwell Automation 2706-LV2P_LV2R_LV4P_LV4R DL40 PLUS USER MANUAL - Manual (Page 123)

Remote I/O Communications 8–31
Publication 2706-6.1
Return Clock or Date Data to PLC (Block Transfer Read)
The following shows the format of block transfer clock data returned
to the PLC from the DL40 Plus. If Block Transfer Read Length is
set to 0 in the PLC program, the DL40 Plus returns 2 words.
WORD 1
17 16 15 14 WORD 0
Block Transfer Read File
Any Size Rack
Clock/Date Data Bit = 1
Diagnostic Code Hour/Month
Minute/Day Second/Year
When sending clock data to a PLC from the DL40 Plus, the
Acknowledge Bit never changes state (goes to 1) even if MSG ACK
is set for that message.