This is example for Smargo cardreader but you can use ins7e11 = 15 line on PCSC and internal cardreaders too! I had excellent results with Omnikey 1021 and Sky Italia 09CD card. ECM dropped to amazing low 70ms!

[reader]
label = skyde
protocol = mouse #you can also use smartreader
device = /dev/ttyUSB0
caid = 09C4
boxid = 12345678
detect = cd
mhz = 357
cardmhz = 357
ident = 09C4:000000
group = 1
emmcache = 1,3,2
ins7e11 = 15

[reader]
label = skyit
protocol = mouse #you can also use smartreader
device = /dev/ttyUSB0
caid = 09CD
boxid = 12345678
detect = cd
mhz = 357
cardmhz = 357
ident = 09CD:000000
group = 1
emmcache = 1,3,2
ins7e11 = 15

And this is for PCSC reader:

[reader]
label                         = SkyIT
protocol                      = pcsc
device                        = 0
caid                          = 09cd
detect                        = cd
mhz                           = 357
cardmhz                       = 357
ident                         = 09cd:000000
group                         = 1
emmcache                      = 1,3,2
ins7e11 = 15